If you're going to essentially pause feature development for years to do it, as a customer I expect something besides some self-congratulatory blog posts.
Out of curiosity, what kind of features were you waiting/hoping for?
If you don't trust them and are unhappy, your only choice is migrating away. Vote with your wallet and don't host your email with someone you don't trust.
"Years-long feature development freeze due to infra changes" is such a ridiculous claim that it's hard to see this as anything but purposeful and intentional lying. Shame on you.