Oh for F**K sake why the hell would EA want them delisted unless its the start of making them origin exclusive.
I'd say it's quite likely. Although I don't think the average Origin customer is the ideal buyer of such games.
It's also possible that EA have plans to launch a new game in the Syndicate or Underworld franchises and want to regain absolute control over the ip and selling rights.
EDIT: I admit I'm a bit shocked at the apparent lack of reaction from the GOG customer base (usually so fast to jump at certain controversial issues) :(
I hope it's because many are not used to pay attention to the "stickies".