The issue I see with hail is that unlike, say, rain which can activate swift swim and cover fire weaknesses without a conflict of interest, hail has to prioritize whether slush rush or Aurora veil will get the 8 turn bonus. I want hail to work, but I think it's gonna struggle to support both roles.
Using hail means Slush Rush, and Slush Rushers don't need constant Aurora Veil, that would only help them get onto the field. It'd go like:
Turn 1: Alola-tales enters field (8 turns of hail remaining)
Turn 2: Alola-tales uses Aurora Veil (7 turns, 5 turns of Veil)
Turn 3: enter Slush Rush or other hail user (6 turns of hail, 4 turns of Aurora Veil)
That's more than enough turns to do some damage. It's enough for, say Alola-slash to setup with Swords Dance
But, the current number of Slush Rushers is fairly disappointing... it'd at least be nice if we got a special one. Glaceon and Vanilluxe could have been really good, but the former is still not even viable in PU and the latter feels kind of redundant when Alola-tales is simply better as a hail setter.