There was some drama a few years ago where Proton provided IP addresses of some activist to authorities, so yeah, they will do so just as much as Apple will.
In fact, this case shows that Proton Mail is exactly as private as advertised. The emails of the user stored on our servers could not have been shared because we don't have a access to them (due to zero-access encryption: https://proton.me/blog/zero-access-encryption). Of course, as any other legally operating company, we need to comply to local legislation, and the very little data we need to have (more in our Privacy Policy: https://proton.me/legal/privacy) will be shared if we're presented with a court order we have no legal grounds to contest. Proton doesn't provide privacy by refusing to cooperate with the law enforcement, but by not having access to the data.
On the other hand, as described in the blog above, Apple does have access to your data, and uses some of it to serve targeted ads: https://proton.me/blog/iphone-privacy.
Given that the blog post mentions apple’s ad business, I had no reason to believe that “just as much” somehow meant less than what was the subject of the discussion.
On the other hand, as described in the blog above, Apple does have access to your data, and uses some of it to serve targeted ads: https://proton.me/blog/iphone-privacy.