Why doesn't windwall block Taric's dazzle?

It isn't a projectile anymore.

Because his Dazzle is now a laser, while Yasuo's W only blocks projectiles.

Projectiles are defined as anything with a travel time that is not a living unit or a melee attack. This includes everything from most ranged autos to Morg's Q to Teemo's traps.

Lasers, on the other hand, are any attack that is instant and not melee or a ground attack. Lux's R, Vel's R or autos, Zoe's passive, and, yes, Taric's E are all lasers.

Ground-targeted effects, which are a bit less common, are anything that just appears at the spot, and does not appear to originate from the user. They're never unit-targeted, rather always targeting a spot on the ground (Hence, ground-targeted effects). Wards, Veigar's W and E, Soraka's E, and Morgana's W are all examples of ground-targeted effects. Yasuo's W and Braum's W also do not block ground-targeted effects.

Before the rework it was a projectile, now it is a linear AoE laser in the vein of Finales Funkeln, Life Form Disentigration Ray, or Arcanopulse

Taric's hair and cape are permanently in the wind, he too has mastered that technique.

it also cant block projectile kitten

"latches onto face" https://youtu.be/G0b5axu9eYY?t=80