I fear with aoe being uncapped the legendary glacial fragments is going to be superior to freezing winds.
Blizzard I ask don’t let that happen. Buff freezing winds by decreasing the current 2 second finger of frost proc.
Playing glacial fragments is BORING and ironically playing freezing winds is FUN.
Glacial fragments might be the play on fortified weeks of some dungeons if you have a strong single target comp. Other than that it won’t be because freezing winds is better single target, cleave, icy veins uptime, and doesnt lose all its damage if the tank walks out of your blizzard.
It already is superior to FW on 5+ targets, even in its current state.
The buff wouldn’t change reasons why you wouldn’t want Glacial Fragments. The buff makes it excel even more in its niche while covering none of its existing weaknesses. I think it’ll be a good choice on some Fort weeks assuming your group can cover for you on ST phases.
But 4% ST buff! Surely that will cover all the weaknesses of Frost for the past 2 expansions… >.<
In fairness, Frost is ridiculously strong on all M+ in PTR right now, and this is probably the most relevant it’s been since like 8.2. It can handle any affix combo reasonably to extremely well; & the flexibility of choices between FW & GF for dungeons (or sometimes, swapping between both in the same dungeon) makes it a very solid pick. For a pure DPS class it offers great role compression via Lust, a buff, Curse removals, and baiting to then invalidate many mechanics that are otherwise extreme healer checks or even fatal.
Sanguine and Necrotic are probably the most annoying affixes it has to face as these usually cause more than normal levels of kiting which lowers Blizzard uptime (so by proxy, FO uptime). However, all specs have certain affixes that soft counter them, so this isn’t necessarily a bad thing. If anything it gives more incentive to recalculate routes or comps to optimize DPS in the face of these challenges.
The ST buff is probably thrown in for raid, where it could use some help given how the fights in this tier work. The entire raid tier isn’t very ranged friendly though, and its ‘balance’ is entirely dependent on the dom shard set bonuses. Interpret that as you will 
The consensus on the Altered Time Discord is that FW is still the best, even with the aoe cap change. Frost already has awful single target damage and you’re just making it worse by losing the FO/IL combo 2-3 times per boss. If you are in groups that are pulling massive amounts of mobs maybe it wins but it’ll still suffer on bosses.
GF will keep being niche and good on high keys with a massive puller tank. You need mobs to have hp enough to tank the amount of damage output and a key high enough that allows your full aoe build in detriment to pitful single target damage. That usually happens on fortified weeks on DOS, NW, Halls and SD above 21… on those keys the amount of time dealing with mobs is way bigger than the amount of time dealing with bosses, and the build gains value.
Azuna did that overall on DOS, where his tank almost did like 5 pulls during the whole dungeon, on top of that the comp had a boomkin and a rogue to compensate the super hiper mega lack of ST damage Glacial Fragments build has.
But its good, and even better now with uncapped aoe. however the real reason frost will be the best spec is the uncapped orb with freezing rain build resetting it almost instantly (and since you can swap between venthyr or nf anytime now, your st wont suffer that much).
So… on top of having the best constant control of the game (which nullifies almost every affix), the uncapped orb will garantee an even higher aoe on every pull.
Dude… don’t EVER reveal that something is fun. If WoW devs see this, they’ll nerf it into the dirt. To Blizzard, fun=overpowered.
In low keys -12-13 for me now, GF outdps other mages FW by a wide margin.
I see, good know, i can’t give an opinion about that, never did such a low key this season.