I don't understand how this is related to ProtonMail. It reads more to me like "never use Chrome [if you care about all of your web content being sent to Google]". Sure, ProtonMail is likely to have personal, private stuff in it but so does a bunch of other things, eg. internet banking.
It's related because it's being reported by a user of ProtonMail into a ProtonMail forum. What you say about it being relevant to just about every page is definitely true.
Then the title should reflect this. At the moment the title seems to imply (wrongly) that this is something specific to ProtonMail. I took the comment to be about clarity.
That's a problem of HN site norms. Mods here specify that titles shouldn't be altered by the submitter.
IMO there should be an original title and an edited title (and users could optionally display only one title of they requested) ... but then there's lots I'd change ...
Right that would be nice but people usually submit the original subject and the admins usually enforce that they do. Often you can get away with light editing for clarity when submitting a link but it's just something to be aware of.
It's related because that translate feature was disabled for those languages, but Google Chrome decided to disregard that specifically on ProtonMail and send the whole thing to Google servers anyways.