I get what linking is and (again) I'm *very* familiar with GPL licensing, but I still fail to see correlation. What the enhancement request is about, is compiling MBII's cgame*.so (that doesn't contain OpenJK bits, as stated in earlier explanations, just engine hooks and hax removed) for different architectures. + eventually, any other MBII-specific, non-openjk things.
Now, having that for architecture of choice, users could just compile rest components of OpenJK for that platform (for example, openjkded), and being compiled for the same architecture (for example, arm),
openjk.arm would use MBII's
cgamearm.so, just like openjk.i386 uses cgamei386.so now.
So, basically, everything as it is now, but for different architecture. If you don't link to OpenJK binaries on i386 and it works (cause MBII's
cgamei386.so is compatible), why it wouldn't work on other architecture without additional linking?
Or are you speaking about compile-time linking OpenJK (during openjk binaries compile) *against* your (MBII's) cgame*.so? Then, this applies:
https://www.gnu.org/licenses/gpl-faq.en.html#GPLIncompatibleLibs
...which mean that you just create another text file, where you grant users the exception to link against YOUR library (cause you're copyright holder of MBII's cgame*.so).
/Cat Lady
// Edit
And don't get scared by:
https://www.gnu.org/licenses/gpl-faq.en.html#FSWithNFLibs
...it just means that they don't like it, but can't do anything against it, as it is not business of GPL'ed part. And yes, I'm not a fan of how it is phrased, the "no part in Free World [sic!]" might be misleading. But it is just personal opinion of Unix Beard that wrote the FAQ at the time.