Would that be a full-on interview as if they were applying for a job, or just some kind of "cultural fit" screening?
It seems contradictory to me: if the hire is important enough to spend a lot of money on (even via an earn-out) then why alienate them with uncertainty about the offer?
I guess the assumption is they don't have a better offer?
But if a few key employees get together then don't they have the ability to scuttle the whole deal? "Keep doing this thing that Apple was willing to buy, but on better terms, and look for a new buyer" sounds like a pretty good alternative to "take Apple's earn-out on Apple's terms with nonzero risk of getting nothing."