Hmm.
I still dont see how Tassadar is back to Top Tier with his changes, though. Do you need a bulky AF team like they had for him to work?
his shield is obnoxious, and that's pretty much why
They shifted Tassadar's main source of power from Archon -> Shield. This did two things. First it made him more consistently powerful versus power spike-ish as his shields are a low-cooldown ability and he's not relying on a long-cooldown Archon to be effective in engagements. In a game that at the competitive level seems to be more about consistent skirmishes than full-commit teamfights these days, that's quite important. Second it makes Force Wall viable because Tassadar's power is now in his base kit and not almost solely in his R and lategame E talents.
Force Wall is amazing against certain heroes and compositions, making Tass an even
more flexible and reliable pick. But Tassadar could never take it in the past because he was balanced around how insanely powerful Archon was.
Force Wall was like Divine Shield was for so long. Always a pretty good skill but the hero it belonged to was balanced around their other heroic which had such an insane amount of power (for uther it was Sprint + big radius DStorm) that if that hero didn't take said other heroic, that hero was bad because their base kit wasn't good enough; essentially, the hero was being saved by their imbalanced heroic. Blizzard removed Sprint from Uther and nerfed D-Storm but increased the power of Uther's ghost and lategame talents, baking more power into his base kit rather than in the D-Storm combo. This let players pick D shield without feeling underpowered and now it's widely seen as one of the best skills in the game.
If Blizzard buffed D-storm a smidge and nerfed his ghost a little bit I think Uther would be in an awesome place. Right now hes kind of imba.
As for Tass I think Blizzard did the only thing they could. I think it's kind of boring and it would have been way more interesting if they had re-designed his talent tree to let you pick a more support or assassin spec but it's clear that they didn't want to make him more support-based through talents only because then they'd still be running into the QM queue composition problem if somebody didn't pick the support talents in a game. That being said their changes were very effective with regards to giving him a more balanced curve of power and giving him two viable choices at level 10, which should be their goal for every hero.