TN visa. ownership confusion

hi,
planning to go on TN. Employer planning to buy a company in 3 months but wants to hire me now, since he does not want to wait for 3 months. Employer would ask the current owner of that company, to give an offer letter and eventually buy the company from the current employer in 3 months.

Pretty confusing scenario !!

If the ownership changes, do I have to apply for a new TN?

GEt TN with curent owner. When new owner comes in he buys all "rights and obligations" including your TN sponsorships, so it remains valid.