Ok, we’re dealing with multiple intersecting issues here. But yes, you are correct in that jumping from a 1.12 dataset to a 8.x dataset you are going to encounter problems. Problems which have largely been addressed by the Classic WoW Devs already.
You also are correct in regards to the datafiles and some other assorted code for Classic is very likely to be unique to Classic as it doesn’t need to worry about being compatible with 8.x gameplay. This isn’t news, we’re aware of that. You’re ignoring what we were telling you because you seem to be failing to make some important connections and associations.
Retail has the code from the image cache database for the pre-1.12 (wearable) items because they remain wearable in game. THAT portion of the DB specifically needs very little attention all things considered. That 1.12 code is NOT “a mess” because it looks exactly like the code for 8.1.X items in the 8.1.x DB when you look at it from the code side. (Not to be confused with what the end user sees) Besides which, even if the above wasn’t valid, the work being done by the Classic WoW Team would ensure that a 8.x Compatible version is available to work from.
As the image database formats changed between versions of WoW, their formatting changed in the item cache along with everything else. Although you would be correct to point out some items do not have the same textures now as they did in 1.12.x, that’s fine, Retail can keep the new textures.
You only get a problem if you try to jump from 1.12 data straight into 7.x (Which the presentation talked about), or 8.x which is the current “Modern Client.” (Good odds that the Classic project is, or soon will be, on the 8.1.x code base. As I’m sure they worked out how to handle keeping the client/engine code synced between the two projects, they even seem to have (vaguely) alluded to that in the presentation. Do NOT confuse the engine with the gameplay data.)
But that only covers wearables, there also are consumables and their assorted Icons, THAT could be a lot more of a grey area, particularly after the “recipe streamlining” they did recently for the older Expansions. That just potentially made things a lot more difficult in terms of integration with Retail than it was previously.
Alternately, they just made it easier. If they completely modularlized every Expansion Tier and their professions with each Expansion being its own module. Now they just need to plug the Classic Data back in as its own “Module” for Retail and off they go on starting to implement Retro-Vanilla-in-Retail.
So short form: “Wearables” from 1.12 still exist in 8.1.x and their status is “just fine” in the item DB, making them re-obtainable isn’t going to cause any problems for Retail at all from that quarter.
Vanilla “Consumables”/crafting mats are potentially a different matter entirely, as Blizzard did forcefully removed some of those from their (player usable) DB as of 8.x and no longer exist in the player-side of the game.
Yes, but again, you’re not fully processing what you were told in the presentation, or what we’ve been saying here. The Terrain Engine had changed how it operated between 1.12 and 7.x (There probably were major formatting changes in Wrath to accomodate Phasing, and again after the Cataclysm) which meant the 7.x engine didn’t understand what the 1.12 data was telling it. So “Weird things happened.”
Weird things which the Classic Dev team has been systematically going through, identifying, and correcting. That Classic WoW Terrain Data, once it is “ready to launch,” would also be “ready to roll” on Retail as well, albeit with a few additional tweaks to certain data pointers. Mostly in regards to which “world tab”/“world server” they belong on, as Classic WoW is running them as the “Prime” locations, while Retail would be using them as a different/alternate location option–they don’t want it to over-write all their work from Cataclysm or in BfA. That particular change should be positively trivial to make, with a time to implement measured in minutes. Although Blizzard QC will make it take weeks.
The difficult part is determing how players get there. What rulesets apply to them while there. How the Game Engine is to handle players in those areas, and on and on. It is the Game Engine aspect that makes things get complicated quick.
As our preference would be that they turn up in the Retro-Vanilla-in-Retail Content as a level 1, and that they basically have to contend with the 1.X patch level talent trees, abilities, and everything else. In other words, that “Paralell use of different Mechanics” things I mentioned way up this thread.
I guess in some repects, given Classic should be its own thing. Allowing non-Vanila Race/Class combos to wander around “could be allowed,” although the Space Goats, Blood Elves, Goblins, Worgen, and Pandas(as well as the 6 newcomers) would all need “a race-change” while in that content. (Yes, that likely means Alliance Shaman and Horde Paladins for that version if they went that route)
Not sure how they’d address the Monks, Demon Hunters and Death Knights on the retail side though, other than possibly locking them out because of the cascade of changes that letting them in triggers, above and beyond anything the Shaman <-> Paladin faction crossover would trigger.
Except you’re forgetting something here: Classic WoW already moved the 1.12 data from the old 1.12 data format over to the 8.1 format. Once Classic “is done,” that work also is done. At that point they’re moving from 8.1 to 8.1. They’re not having to re-invent that particular wheel, Classic alreay did the work.
What they’re having to “re-invent” at that point is finding a way to incorporate the Classic (8.x) data into the (8.x) Retail Client (as that “Retro-Vanilla-in-Retail” concept), in a way that satisfies both Blizzard and the community at large. And that is where the zombie bears come out and start eating people while Inquistors from Spain go about conducting Inquisitions.
But as I think more about changes that seem to have happened in BfA, I think they’re already laying groundwork to possibly do something like the above. They just haven’t had a team decide to try to actually do it. I expect the next developer Team to come up “at lose ends” soon is the one working on Classic itself right now. Although I think their sights are on Classic TBC, not the monster that integrating with Live would be.