I guess it happens all the time, assets getting lost in the acquisition/merger processes.
There was a decades-old company in Poland named Star, which produced trucks in Starachowice, it has been acquired by MAN and they redirected the old domain star.pl to a wikipedia page about Star (quite an interesting move btw), but this year they forgot to renew and it started expiring, though it got reactivated half-way through.
But I've seen it lots of times, domains getting dropped after merger or rebranding. One time I caught such a domain and a few years(!) later I got an e-mail from the new owner of the company previously owning the domain asking me how to access the domain because they lost the login details...