I don't really think this update will change him that much except make him a better jungler for those who dabble in bringing him to the woods. The Q heal is weaker if you don't have charges but it can get more charges faster, costs slightly less mana late game, and has better scaling late game because it was changed to scale off 1% max hp rather than 1.5% bonus hp. At max stacks, that is 5% max hp when before it was 4.5% bonus hp. While the "gain a charge with each hit of bravado" part sounds kind of broken on paper, he will still have the problem of running out of mana in about 10 seconds if he spams it.
The mana changes are a huge buff. Currently his mana scales up to 22 from 5. The update is up to 22.1 from 8.5. The early mana sustain really helps his currently weak early game.
I'm kind of indifferent towards his stun changes. The cooldown change doesn't really do much for him late game so I think the 17 second cooldown early for 13 second cooldown late is a slight nerf. The damage increase makes his top lane and jungle play stronger while the cooldown change makes his late game support play a little weaker. Overall, the E changes probably won't really affect my play on him because I use his E very reservedly early game due to him being pretty much worthless when it is on cooldown until he can get in there and proc his passive when he gets a little tankiness.
I like the changes, but I am honestly scared that Taric will become meta. He is currently the least played support there is with about 1.5% pick rate. As such, I have yet to run into a problem of him being banned or picked by the enemy before I get the chance to take him.