Not sure if this is helpful to you, but jitsi offers end to end encrypted video calling, which is the sort of thing I would expect from ProtonMail, should they offer it. e2e encryption on video is, of course, quite heavy, so expect some small delays when enabling it.
There is a corporate solution with support, called 8x8, which is also available on https://meet.jit.si if you are not wanting to use the "free" version
Not sure if this is helpful to you, but jitsi offers end to end encrypted video calling, which is the sort of thing I would expect from ProtonMail, should they offer it. e2e encryption on video is, of course, quite heavy, so expect some small delays when enabling it.
There is a corporate solution with support, called 8x8, which is also available on https://meet.jit.si if you are not wanting to use the "free" version