What? Conkeldurr is most definitely an Excadrill check. Doing like 60% with a priority attack is in he same vein as Scizor's BP on Salamence, and it was laregely regarded as a check.
Maybe it is just me, but I find priority to be an adequate way to deal with Blaze. Since I run an offensive team, it has difficulty finding an opening to switch in, and suffers from rocks on top of that. Between weak hits, LO (which Blaze is not nearly as threatening without), Flare Blitz recoil, and Stealth rock, Blaze is being worn down pretty quickly, enough for priority to wrap things up.
Scarfers are few and far between, but other ways to check it include Scarf Terrakion, ScarfLati@s, ScarfGar (who is also immune to HJK), and ScarfStarmie. The latter two are quite rare this gen, and have been since late Gen 4, but they are still useful.
Prankster Thunder Wave is another viable option aka Thundurus.
And while HJK is a matter of prediction, Flare Blitz is not. Blaziken will lose about 30% of its health from Flare Blitz if it KOs a sweeper with HP similar to its own, which is pretty significant. The only way to circumvent this is Blaze Kick in Drought, but that is Drought's doing, not Blaziken's.