I'm not sure in this specific case. They could choose to pay the employees some portion of the funds.

If not, the owners are likely liable to be sued for "selling in effect" without paying equity holders.

Presuming the company becomes a defacto subsidiary of Nvidia (even if not legally so)

My guess, without researching it, is they will compensate existing equity holders to avoid that possibility. I mean the valuation multiple is enormous, it's worth it simply to derisk the legal aspect.