Hi,
yes of course, something like that. The important fact is that there is a sort of validation: no checkbox flagged? -> no login’s button clickable! Or something similar, you are of course better UX designer than me. I believe that for sure the warning text should be customizable, in theme’s settings or at least by string translation.
Unfortunately, the adaptation of the sites to the new EU legislation will be invasive and complicated. Site managers / developers should verify that EACH plugin (and themes too, I suppose) are compatible with the regulation. I believe that as is, due to the fact that the login process stores users email in DB without any warning, the integration between BF apps and your theme’s social login module doesn’t fit new EU rules and will be not usable. Fixing this issue with social login module will be over the skills of so many theme’s users, so I asked your help. And your quick and professional reply came as usual. 🙂

Thanks,
G