I actually read that he was suppose to return to the set on Monday, so I don't think they finished everything. I don't think it matters at this point regardless since nothing can be done.
F&F will still go on I'm betting, they will just kill off his character (I don't see him living after this one personally as the next movie is them getting tracked down and hunted) So this could have been the last F&F for him or in general and if not the next one will just be about his team seeking revenge.
OR, Brian's child, boy/girl, takes on his legacy and have her own story.