They undeniably added a great deal of things people didn’t like, as well.
I don’t think it’d be Classic at that point.
While I do agree that adding new things would potentially make a very good game, I don’t think any reasonable person who has been playing WoW for long enough would actually believe that Blizzard is capable of adding the right things.
Remember, these are the folks that used engagement metrics to measure enjoyment, locking character progression behind content no one liked in and marveling at how much everyone loved the content because everyone was doing it.
Take the worst parts of retail and add them to Classic. That is what Blizzard would bring you. I guarantee you that no matter what you think is cool, Blizzard would ignore your feedback and add whatever they wanted, and you wouldn’t like most of it.