I've been hearing a lot of people discussing that the legacy server should be changed to add or remove features that were never apart of vanilla world of warcraft, as well as this whole thing about how a TBC server would follow vanilla after. These ideas seem very scary and felt like ranting about them so I made a video if anyone is interested. I know this is a very sensitive subject so would love to hear your thoughts. I personally would play on a legacy server as well as Legion, but it's nice that Blizzard are actually now considering Legacy servers IMO:
https://www.youtube.com/watch?v=ulihURHLPvU