These two responses both seem very solid to me. And obviously don’t even hint about the possible acquisition, as virtually everyone in this thread has noted.
Even if you do have that level of trust in your boss, ultimately he (more than likely) has to answer to someone else, and even if they are the ultimate power right now, there’s nothing that says they will still have the power to make such decisions after the merger.
And further more - call me sad if you like, but I’ve always believed that trust is not immutable - EVERYONE will betray you, given the right circumstances.