Just spam from the proton team, they really are notorious spammers. How could anyone trust a "privacy" company that does such shady marketing? Look at antics on Reddit for a primer sadly now on linux org even.
Mind elaborating a bit? This is the first time I'm hearing this. I thought their entire selling point was privacy and end-to-end encryption for emails.
Apparently Protonmail have been cozying up to Trump as well. I've heard Tuta to be a good alternative I'm trying out. They are also encrypted but I think they also spam you with their "plans".
I'm four days later responding, but for what it's worth I find this source to be damning of email as a captured protocol, but meh on the implication that the Proton management is cozy to the Trump administration. Rather just clumsy in the quiet part out loud way.