It's all appropriate (and my preference is to actually "merge" plans together, lest the money "leak" and not be available for retirement) BUT - these are issues that should have been discussed, decided and documented BEFORE THE ACQUISITION TOOK PLACE.
Having been doing this for more decades than I care to count, I'm not naive enough to assume it will ever happen in the right order, but I can still put my two cents in.
In the organization for which I am currently providing my services (a TPA/Consulting/Actuarial/Technology company) we are trying to educate clients that corporate transactions that may have plan impacts need to be handled earlier - and we are trying to gain their trust so that they will look to us for plan advice when such is contemplated.
After the fact decisions can restrict options.