Earlier quoted context omitted.
They wouldn't extend an offer to you in this case. Acqui-hires have no upside for employees and barely any for founders. Some small return to investors to sign off on the acquihire. Usually most people still have to interview for their jobs.
Acquihires do often have employee upside, in the form of large stock-based compensation grants or bonus payouts, typically spread over a vesting period of several years. There's no point in the acquihire if you don't retain the employees, and relative to the cost to acquire the company these payouts aren't huge. You're right that often people do have to interview to remain employed (and thus to receive these benefits…
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."