I don't think there's significant downside to evolving now. Fast TMs are cheap, so you can always swap SD Tyranitars into Bite, but you can't get SD Tyranitars after the weekend ends. I think S/FP is a pipe dream, but if you're really scared of it, maybe save two or something. Darkrai will out-DPS S/FP Ttar anyway.
Wait for Snarl/Foul Play Tyranitar or evolve to Smack Down?
So i have a few 90%+ larvitar that im now wondering if i should evolve to smack down.
I already have 6 with bite crunch and 6 with rock moves so i dont NEED any new ttar. However, smack down is exclusive and it MIGHT become more useful in the future. On the other hand, im scared Niantic decides to release a new Dark type moveset for ttar but not let you TM it, so basically screw anyone with full teams of bite crunch Ttar.
To add, there is also Darkrai, Weavile, Rampardos and Rhyperior, all competing with Ttar and depending on how good they are, one or both of the Ttar movesets might be outclassed.
So what should i do?
A: Evolve for the sake of exclusivity and to replace some 80%+ with 90%+ on my Rock team
B: Wait for a possible new Dark moveset?
C: Just not care since they might rebalance moves all together for PvP and crunch might become good and rock slide bad (rampardos best move)
I usually not indecisive and tend to be very patient, which has given me 100%iv pokemon with exclusive moves like gengar, venusaur and tyranitar. this time however, i am being rushed and so i reeeeeally need help from experts
Answers
Here's the thing about those pokemon, all are either glass canons (and in the case of darkrai is a legendary which demands rarecandy), or rhyperior, who is inferior to tyranitar and has better use as a ground type. We already know these movesets of these pokemon. And while shadow ball darkrai even out DPS's mewtwo (wow) agaisnt ghost and psychic types, its still a glass cannon statwise despite its type offering higher effevtive bulk than mewtwo agaisnt ghost types and psychic types depending on moves. Theres actually a number of situations where tyranitars far greater bulk actually lets it in reality out dps pokemon like weavile, eventual rampardos and such.
and its not like (if it gets a better moveset, which seems VERY unlikely) it will make its current fantastic movesets any less good. I was going through a similar debackle a while back when I hatched my perfect machop and more recently with my perfect dratini. Its not like metagross where it cant even compete with its event set/
I'd say go for double rock, while now that the birds have come and gone, its not likely Rock set tyrantiar will become a powerhour legendary killer until we get gen 5's legendaries unless the birds come back again, its still an exclusive move that is boosted by a common weather type. IT's pretty good against Houndoom (dont know if its still a tier 4) and marrowak raids right now however
The thing is, double dark tyrantiar actually has match ups through out all generations, the only exception beign gen 6 but thats largely because it didnt have a lot of legendaries to begin with. gen 7's main trio is actually weak to dark as well. It's a lot more future proofed in both being supreme in stats and having a lot of advantageous match ups (when you consider double rock tyranitar and double dark tyranitar, it has so many match ups against legendaries in every generation, all of them in gen 1, a lot of gen 2 and 3, 5 in gen 4, double dark's not to good here agaisnt anything but the normal/psychic meloetta forme while double rocks' great agaisnt reshiram, kyurem, thunderous, tornadus, gen 6 double rock's good agaist yveltal and volcanion and double dark's not good agaisnt anything, and in gen 7 its the reverse double dark agaisnt the main trio there but not much for double rock) making it one of the most reliable and safe options. Theres really no way to go wrong with its current movesets.