Other methods have been discussed. For example, mods could be crippled. DBM didn't exist back then, and the other boss that did that I don't remember the name of, didn't do as much back then as DBM does now. If our goal is to recreate the experience as it was, then obviously not having DBM would be a reasonable way to accomplish that. DBM simply existing, makes the game today easier than it was. So disallow it. Again, this is completely consistent with the spirit of vanilla. Remember one-button-decursing? That was nerfed. They crippled the capabilities of the modding API to disallow that because it made the game too easy. So what if they cripple it a little bit more to once again make the game less easy?

1 All expansion guides are written in the Battle for Azeroth beta in order to have them ready on launch day. It's important to note that betas can be buggy and unstable and may delay and even halt our progress on the guides. Furthermore, the time between the start of beta and the announced release of Battle for Azeroth is much shorter (by about 2-3 months) than past betas. As a result, our primary focus is to have the Leveling guides updated by the launch, and only if those are complete and time remains will we work on updating the remaining guides. All guides not finished in beta will be updated post launch. You can read more about this here.
Good question. Me personally, when I use a new strat from somebody else, I always read thru the strat, and in the case I really need to level some pet, I then (likely) exclude strats that are mentioning things like “RNG”, “risk”, etc. But: I’m always happy (when using a new strat) when I see some detailed infos, so that I can estimate what is going to happen. But YMMV.
FYI: If you’re returning to WoW after an extended absence prior to patch 5.0.1, it’s possible that you’ll have more than the maximum pet limit and/or more than 3 of a kind. However, this will be the only time that you’re allowed to surpass these limits. You will have to pare down your collection, eliminating your duplicates, in order to add new pets.
Nov 10 well i tryed i was hoping to comeback to wow after being away since cat but my only real interest was pvp. seeing the state its in now i can see it's not worth bothering with and i feel i've given it enough time. the only choices i see for pvp is to twink so i can beat on kittens (cause i'm so 1337) or be so under powered i'm useless as i watch the twinks decimate my team. i didn't return for the american gladiator experience. it's a shame i missed legion i feel i would have like it better.Piale5 Nov 10
I consider myself a purist in that I would prefer classic to be released as close as possible to the original. Where that is on the spectrum of patch content will be up to blizz. I'm also not vane enough to believe that any single state of the game is the "Ideal" location we should be aiming for. There is common ground that we can agree on, and I would welcome more than a few changes as long as they are made in the spirit of keeping classic on the vanilla rails.