Weavile's always been viable. Even in post-Aegislash XY, it was sitting at B-, early ORAS had it sitting at a solid B rank in viability, and today it's sitting at A- in viability. It's always just had issues of being high risk, high reward since it has zero defensive synergy and can't switch into anything, and all of its counters are pretty common (i.e., Keldeo, Clefable, Azumarill, Mega Scizor, Skarmory, etc.). Resisting no priority outside of Ice Shard and Sucker Punch (both of which are rare), while simultaneously being maimed by some of the most common priority, does it no favors either. Still though, it can check a solid number of things, and can 2HKO a large portion of the metagame, even if it is a glass cannon. It's also good at pressuring hazard control 'mons such as Starmie and Latias, so it does fit well on offensive teams. It's got a lot worth noting so it's a solid HO Pokemon for sure.