None of those reasons are good enough to give them megas over a dozen other good pokemon. Wish lists are fine, but since that's not what we do here, I'd prefer to hear why those 2 before say, Altaria.
My personal list of pokes that make sense is:
Kanto:
Machamp
Golem (other trade to evolve pokes got one)
Dragonite (cuz other psuedos got one)
Johto:
Starters (cuz other starters got one)
Skarmory
Hoenn:
Ludicolo
Shiftry (version exclusives like Pinsir and Heracross)
Milotic (cuz gyarados)
Salamence
Metagross (Psuedos)
Sinnoh:
Starters
Gallade (Gardevoir)
Unova:
Starters
ANYONE! (cuz it needs the rep)
Kalos:
none, at least until gen 7 (these pokemon haven't established their image yet, and giving them megas would completely erase the originals. Diancie was obviously always meant to have a mega, and that's her thing, but the rest I'd prefer not)
I'm sure most of these won't come with ORAS, and some others will, but these pokes are the ones that are most likely imo.