No, it won’t change, not dramatically.
It has been like this since Wrath, because it’s a reality of the genre.
They’ve added things (Garrisons, then Class Halls, then the Faction War, then the Covenants), but those are all pretty rinse and repeat, and they turned out to be a good mechanic for borrowed power. We’ve had “the legendary” since MoP, this, too, will return.
Borrowed power will remain. Leveling will continue to be Story Telling mode, and a secondary, introductory activity. RNG gear is here to stay.
Reps will not be account bound, it will remain “alt unfriendly” in the opening stages.
And the reason for this is that they’ve found that all of these things “work”. Players LIKE this kind of content, people LIKE to play WoW, they just need “something to do”. Repping up, chasing RNG, filling in bars and cosmetics and pet and whatever, folks like to do that. Folks like daily content that they can do “every day”, or at least “often”. Log in, “something to do”, something that is NOT “free form”. Something structured.
The Emissaries, the Callings, the Korthia and ZM weeklies are the implicit “catch up” mechanic for those that can’t play every day. You can play once a week and only be “50%” behind, a far cry from 1 in 7.
They did a really good job this expansion segregating the character power and the cosmetics. Remember all the teeth gnashing about Anima early on? Well that’s certainly not a problem now, and never was going to be a problem.
SL was great at supporting “stop and go” play. How far are we in to this patch, and how many players have already got KSM? Quite a few I’m sure. The dedicated few with a dedicated core.
All of the other nonsense about “must have…” turned out to be…utter nonsense. None of it was “required”. People succeeded without spending every waking hour in the game, “doing all the chores”. SL rewarded casual play by dedicated players who were able to focus in and min-max to get what was necessary to achieve their goals. SL is HUGE in terms of what can be done, much of it was not done by everyone. That’s a good thing.
Anyone who knows this game know full well they can pop in the last month of the expansion, “do everything”, “kill the guy on the box”, get “great gear”, and go home for another two years. But most don’t do that. Most play early, stick around while its fresh, then some leave, some stick around. Then they return with the new patches, the new content, etc.
The Dev Team always bites off more than they can chew. They should always do this. They should always run out of time and cut stuff out. You think its bad when they cut stuff out, it’s even worse when they leave time on the table with “nothing to do”. That’s even worse. Better to push hard and ship. Better to always aim high.
SL was huge, hard to imagine the next expansion being bigger than SL, but they’ll try anyway.