I don't put as much weight on that as others. Teams across all sport seem to avoid letting a coach's contract expire, and when they do it seems to be more related to a contract negotiation. For better or worse, they don't seem to like having a lame duck coach. I don't have data on this, just something I've noticed.
I could see a scenario where they did that figuring it will be the new owner's decision to make, and their energies were best spent not trying to find a new manager for the team they were about to unload.
But you could be 100% right on this