Perfect Gyarados... what movesets are still relevant in current meta?

I would leave them exactly as is. That's being guided by new gamepress tier lists.

No!

Bite + Hydro Pump makes it a good generalist.

Dragon Tail + Outrage makes it a decent backup against Dragonites.

Bite + Crunch counters Mewtwo and resists Focus Blast.

i just tm'd my perfect bite dragon pulse and got outrage. I am now trying to consider whether to fast tm for dt/outrage or charge tm hoping for dt/crunch

I would be happy with those three. I do have the others at 95% in my collection but wanted my 100% to be something useful.

I'm surprised DT/HP wasn't mentioned. Was that an option?