With a weight of 999,7 kg here is what pokemon seen in ubers it would hit for what base power (only mega sableye's weight is not known yet):
120 = <199,94: every mega and their base form that is not tyranitar, gyarados or aggron (yes including mewtwo, blaziken, the lati's, sceptile, swampert and diancie), landorus(-t), darkrai, deoxys (all), ho-oh (barely), klefki, genesect, sylveon, thundurus(-t), Wobbuffet, Aegislash, Bronzong, Excadrill, ferrothorn, forretress, gliscor, shaymin (both), Whimsicott, blissey, chansey, clefable, cloyster, Quagsire, sableye, gothitelle, jirachi, shuckle, skarmory, smeargle, amoonguss, ditto, cresselia, gastrodon, latias, latios, talonflame, greninja, salamence, espeon, azumarill, mew, florges, tornadus(-t), victini, manaphy, most other things.
100 = 199,94 - 249,92: xerneas, yveltal, lugia, rayquaza, tyranitar, scolipede (barely), gyarados, dragonite
80 = 249,93 - 333,23: arceus (all), mega tyranitar, hippowdon, kyurem (all), mega gyarados, terrakion, reshiram (barely), rhyperior, zygarde
60 = 333,24 - 499,85: (primal) kyogre, palkia (barely), zekrom, heatran (immune), (mega) aggron, bronzong (with heavy metal)
40 = 499,85>: dialga, (primal) groudon, giratina (both), aggron (with heavy metal), avalugg (new groudon counter lol), metagross (for those of you hoping for a viable mega)
So yes I'm quite hoping they'll give it heat crash.