[learnstats2]

This is very different in the US from what I understand; I can't help you there. Locally:

Acquired employees legally remain on their original employment terms and usually have rights to continue uninterrupted work on those same terms. This right also applies if a company is liquidated and reforms.

Given that employees have this legal right, and that acquiring employers must know this (employees tend to be less aware), an acquiring company holding a new employment contract should be treated with extreme suspicion. The company must negotiate what they need, or the employee can just continue on the old terms.

I would suggest an employment lawyer is necessary in that situation. Particularly, since just ignoring the employment contract may constitute implicit agreement.