I think RU is just spoiled by Alomomola as a wish passer? Literally every other wish passer in the game outside of alomo and base audino doesn't have regenerator and they work just fine without it, its not like Umbreon, Blissey, Vaporeon or Florges are bad UU wish passers. Here we have a wisher with more physical bulk than Hippowdon and comparable special bulk to Umbreon, a lack of leftovers really isn't going to hurt it that much. You're playing it down way too much.
And all those calcs are boosted attackers outside of Exploud, it'll be switching in on the boost itself. It can pack fire blast for doublade and 2hko it- I really can't see a mon that can stomach a +2 super effective STAB attack from an adamant base 110attk pokemon and kill it afterwards being bad in RU.
It's not about being spoiled by Alomomola. The most common other wishpasser is Aromatisse which has access to Leftovers, a better ability, and most importantly a pure Fairy typing. Lack of Leftovers does hurt it that much, because a lot of the time Pokemon like spdef aromatisse take like 54% from Specs Exploud's Boomburst, go for Moonblast or Wish and if its the former, an SpA drop can happen and if it didn't, then Aroma can survive another Boomburst anyway because it can Protect to gain 6% back, etc.
Another thing about Audino is its neutrality to Fighting. This is really important because that means it can't stop Pokemon like Hitmonlee or Virizion/Cobalion as they can just muscle through it with HJK, Iron Head + CC, and Leaf Blade + CC respectively. Also, for that calc, I hope you weren't implying that Audino is a Doublade counter. Yes, it has Fire Blast, but does it have place for it? It'll run Wish + Protect that's for certain, Heal Bell would also probably be ran, and the 4th move? Probably either Knock Off or Dazzling Gleam or something. Running Fire Blast will really make it fodder for some Pokemon like Fletchinder, Moltres, Slowking (which can outstall with Scald burns), etc. Maybe if another Heal Bell/Aromatherapy user is in the team, it could afford running it, but otherwise probably not.
Yes Mega Audino is insanely bulky but I doubt it will be the best thing since sliced bread as some people make it out to be.
On the other hand, Mega Beedrill, Gallade, Glalie, Pidgeot... hell, all of them, look very extremely promising. I'm especially excited about Mega Beedrill, I wanna spam that Adaptability-boosted U-turn coming off base 150 Attack which can further be boosted with an Adamant nature. Pidgeot will probably either be pretty good or very underwhelming, and I don't think there's an in-between. Spammable Hurricane looks very promising, and it's speed is impressive, leaving it 1 point faster than Dugtrio (but eh, it can't be trapped anyway so w/e) but a few short from Jolteon. I was hoping it would get 131 speed, but oh well. Hurricane/Heat Wave/U-turn/Roost might be good, but we'll have to see, because it's kind of hard to determine (for Pidgeot especially) whether it will turn out great or not just from theorymonning.
Gallade is looking a bit broken to me, but I'm running some calcs at +2 and it's kinda just not doing enough damage. It can barely 2HKO Phys Defensive aromatisse with Ice Punch and it can never 2HKO Gligar with Zen Headbutt at +2. I'm assuming a set of Jolly SD/CC/Ice Punch or Zen Headbutt/Knock Off here. Additionally, it never OHKOs Alomomola at +2, although I'm not sure if it has a chance with SR, I ran this calc a while ago.
I'll post about some other megas soon.