Well if they sold it to another publisher, then they're not really dying from the customer's perspective, are they? The customer just sees a name-change. I assumed we're talking about support for a game disappearing altogether.
And they would have nothing to 'gain', but if they were shut down in a hurry and all their staff suddenly let go and forced to go out and look for new jobs, who is going to go through the source code of all these games and create patches for the customers to download to disable the need for the game to contact the servers (which of course will also be disappearing)?
I'm not saying they would maliciously refrain from patching the games... I'm just questioning the likelihood of it actually happening.