Hot take, we should consider disallowing the use of addons and focus on simple customizable (see SWTOR interface editor) ways to adjust the player interface to their specifications. This is not only good for accessibility in bringing new players to the game, but also simplifying the process of alt-setup.
When I think about retail’s strengths, it’s really that the class skill-caps are simplified /
more obvious mechanically in so far as there are not convoluted tricks required to be a truly excellent player as exist in many situations in Classic. The upshot of this is clarity and quick access to clean, doctored fun. Engaging with these little rotational loops that the classes are now designed around is rewarding as far as the amount of tactile fun, even if I think it makes growing into the skill-cap of the class less interesting in the long-run ala TBC and WOTLK class design.
(I am not saying that retail classes always require less skill to master, they may require MORE mental hardware, but this comes in the form of twitch-based gameplay design and ends up often being less strategically interesting as a result of being more focused on fast-paced APM).
The annoyance of having to try and piece together a new set of addons or existing addon settings that fit my new character (especially when addons provide a very complex and almost crippling # of options) is enough to put me personally off of multi-classing. I don’t think WoW was about multi-classing at it’s best, but retail at least is here now and this is one of it’s strengths in the trade-off. That said, I don’t think it’s good that a primary concern in bothering to make an alt is whether or not I want to deal with and maintain the initial addon setup when I already need to think about keybinds. Addon settings maintenance between multiple characters also can make for a poor experience especially if you take a break from an alt and try to return to it much later.
Add to this the fact that raid mechanics are made less engaging or sometimes trivial through the use of WA and other addons, and that players are NOT likely to be engaging with the mechanics by simply looking at the environment as intended… and you’ve got even more solid reasons for this suggestion, even if it were only addon-less servers.
Blizzard would need to roll out a patch like this with care, it would have to be married to better core UI and clean customization options.
P.S. If you need to pitch this investment to the higher ups, just tell 'em that instead of social currency undercutting store mounts that with some real investment into the UI and it’s customization templates that you can nickel and dime the players with special “themed” UIs that change the color / tone / ornaments on the player frames, action bars, mini-map etc.
Think about it, $1 for an elite player frame?? $5 for a full N’zoth-themed action-bar overhaul where the gryphons are turned into those creepy eyeballs?? I’M TRYING TO MAKE YOU MONEY BUT THE RIGHT WAY.