After I’ve spent around ~50 games in Masters+, I think I’ve gotten a good idea on what’s strongest in high elo games.
Meta - Zarya, D.va, Lucio, Sombra, Sojourn, Genji
Strong - Cass, Ashe, Ana, Tracer, Echo, Brig, Widow, Sig
Okay - Zenyatta, Winston, Orisa, Bap, Mercy, Hanzo, 76, Junkrat, Roadhog, Reinhardt,
Poor - JQ, Moira, Reaper.
That just leaves a handful of other heroes who are a bit more specific…
Bastion - Obviously disabled right now. Very good against shields, Mei, immobile tanks, and great with Mercy. Pretty meh otherwise, around strong/poor depending on situation.
Torb - Also disabled. Fantastic Sombra/Genji counter, sucks against Zarya and SJ. Meta for dealing with sombra, poor otherwise.
Ball - Really really good at contesting highground and being a distraction, awful against Mei but that’s not a huge idea. Really amazing with high damage/low healing comps like Mercy/Zen. Just hard to use correctly but can be good.
Pharah - Great with Mercy, great counter for grounded teamcomps like JQ rush. Still sucks against hitscans and especially against widow. Decent for dealing with flanker heavy comps that dont have SJ. Okay/Meta teir, more or less.
Doomfist and Mei - Really good together, pretty bad otherwise. Mei is still a good ball counter and is okay against Orisa, but really meh otherwise with a really weak ultimate. Good synergy with Orisa, though. DF isn’t as bad as people make him out to be but he’s still not great. Together they’re pretty strong (around strong tier) because of the Wall-punch synergy, as well as both of them being able to bully really hard, but just not great otherwise. Both are around poor tier seperated.
Symmetra - Must pick for KOTH to use tele to get out the doors and onto the point faster, but otherwise completely useless. Teleporter is good for hybrid first point pushes but it only makes symmetra as good as a strong hero, so you’re probably just better off playing as a strong hero regardless. Damage too low to be useful, turrets are bad, ultimate is still pretty strong though. Turret cooldowns too long to move with push/payload maps.