"We can meet everywhere."
Translation:Możemy spotkać się wszędzie.
This sentence seems to be deleted, that's weird that you encountered it. "Anywhere" is used now as the default version.
Having said that, the sentence can also mean "It is possible that we bump into each other in the restaurant, in the cinema, in the metro, in Thailand..." and doesn't such interpretation (instead of "You can choose the place we meet, I'm open to anything") allow for 'everywhere'?
No, not really. It still has to be "anywhere." Even in your sentence "I'm open to anything," you used the indefinite, although "I'm open to everything," is still O.K.
If you say, "we can meet everywhere," it makes sense if you're speaking in hyperbole, like an exaggeration.
We can meet at the restaurant, at the movies, in the subway, or even in Thailand! We can meet everywhere!
This is O.K. to say because it's understood that hyperbole is being spoken.. But in this DL exercise, it doesn't make sense without this type of specific context.
OK, so let's say that such answer is left as a possible one with a notion that it's only a hyperbole.
As I said, we took your opinion into consideration and now only "anywhere" is 'the best answer', and the sentence we are discussing right now is not in the database - so that's only some bug that you encountered it as an ENG->PL exercise.