They didn't shut down the addons, they broke the parts of the API that those addons used. Blizzard can never ban on an addon by addon basis.
Let's say addon A uses the a function called GetTalentTree() and does nothing wrong, addon B does the same but it does it in a way that is harmful for the game. If you want to break addon B you also need to break addon A since the root cause is GetTalentTree().
They didn't shut down AVR in wrath, they broke the parts of the API that AVR was dependant on. Blizzard has never once shut down an addon, they've only stopped them from working. You can still install AVR today but it won't work.
In case of AVR they restricted the API, yes. But Blizzard has the ability to ban individual addons. Even individual versions of addons if I remember correctly. A long time ago some strings were datamined from the client that say something like "this addon is banned".
Although they have the possibility, I never heard of an addon that was actually banned. Maybe they just use it for cheat/hack addons that are used in combination with external tools?
Of course this whole discussion is meaningless. Blizzard already said that classic will use the new game client, just with old data. This means the addon API will be the same as for current WoW.
Addon blacklisting via DBC was proven to be useless fairly early in WoW life-cycle, it's too easy to circumvent, the last time they relied on it was in WotLK when they had to black list GS as an emergency because it's causing immense server lag, but to address the issue properly they slightly tweaked inspect API by adding throttling which in turn killed GS.
I suspect you will see them break certain things they may not want, but I don't think they are going to use a ton of time doing it. Most of the heavily used addons existed back then anyways ( UI mods and such ) so I don't think they will see it as a major issue.
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R5 5600X | Thermalright Silver Arrow IB-E Extreme | MSI MAG B550 Tomahawk | 16GB Crucial Ballistix DDR4-3600/CL16 | MSI GTX 1070 Gaming X | Corsair RM650x | Cooler Master HAF X | Logitech G400s | DREVO Excalibur 84 | Kingston HyperX Cloud II | BenQ XL2411T + LG 24MK430H-B