Removing the package is harmful to the system. It will remove the mp-fremantle-generic-pr package, the system version, which, in any case, should NEVER be removed if you want your device to function optimally.
Let it be.

And I don't understand your logic, do you want to remove the package all because it's closed source..?
If you don't want closed source, why do you even have a N900? It's filled with closed source components, and they make the device work as it should. It would've been rubbish without it.
As many people say: If it works well, leave it as it is.