I joined twitch in 2013 with the gamer name of FuriousPaul and I streamed speedruns of the classic Castlevania games from 2013 - 2017. Lately my streams have died down quite a bit due to working on Classic WoW leveling guides every day. Although I may come on occasionally and play a random game for fun on my Twitch stream. I talk a lot about WoW speedrunning on my channel, so feel free to follow and hang out to discuss vanilla WoW if you like. Classic WoW will be my main focus for a long time. Unfortunately I will have to wait until Classic WoW comes out before I start streaming it.
For example, the Azure Whelpling belongs to the Dragonkin family. However, it has Beast, Magic, and Elemental abilities in addition to a Dragonkin attack. Different attacks are strong and weak against different family types. Having a diverse spell selection might increase your chances of being prepared with a strong attack against an opposing team.
Occasionally it's also been proposed to re-randomize all the gear. We didn't have best in slot lists back then. People weren't starting out as a fresh level 1 character with a complete list of which dungeons to run at 60 in order to gear as quickly and efficiently as possible. Now, all that data is available. If gear were re-randomized then all of those lists would become useless and thing would be close to how they were. Which is a more important part of the "vanilla experience?" the fact that item X from boss Y has exactly Z stats on it, or the voyage of discovery? Personally I think that voyage is way more important. Do you remember how many points of which stat on the ring or whatever that Darkmaster Gandling drops? I don't. Would it kill your experience if the BiS for every class were in a different dungeon so people had to actually play to figure it out rather than simply consult a spreadsheet? I don't think it would. For that matter, it probably wouldn't be a bad idea to handle it intelligently so that the better gear is in later dungeons. I remember there because some weird cases where level 40ish gear was better than anything that dropped in level 60 dungeons.