They may still be using code that’s in their dedicated servers

don't? Also to be clear, if that's a huge problem, you could also just BSD the code, and call it a day, you would need to publicly release most of the new code based on it, but that's not going to ruin you as a company, especially if people can fix bugs in it for freesies.

Or just open source the next server component that you need. That's the simple solution.