Protonmail’s interface and mobile app is more refined and faster than Tutanota’s, and PM has more features on their free tier than what Tutanota provides on their free tier. Having said that, both are great email providers. I have accounts on both but I tend to use PM more at this point in time.
I’ve seen this story several times now, and it’s probably true. Unfortunately there’s nothing else but the anecdotal story and I wish we had more corroboration from other former employees.