I've opined about the atrocious announcement pages from Google before (across the
board they are offensively sucky), but to give that a rest and speak on-topic about the announcement in question -- good lord what a step back it is, how ugly, insipid, spiritless, and unimpressive it is. Expressive? It's exactly the opposite. Material team, what have you got against shadows, soft bevels, borders, those 2px worth of adornments which carry the weight of gold in terms of communicating clickability, state, different types of buttons, providing instrumental cues and abstraction about everything, why have you failed to learn from UI/UX of the decades behind you?
It's even infecting Flutter, because it wants to push Material. This is genuinely depressing. And makes me appreciate the command of Steve Jobs, the guy leading Stripe, etc. because when you see abysmal offerings like these, you just can't help to.
And it's phenomenally hard to not be judgmental about this, because after release after release it shows they are not learning.