> e.g. by patching the kernel's text at runtime to remove the instructions

Or simply by marking the module as GPL even when it isn't. There is plenty of precedent for stronger measures (like embedding a copyrighted & trademarked logo image in a console ROM) being permitted when doing so was made necessary for interoperability.

There are decent security-related reasons to make this change, but the prospect of complicating access to select kernel symbols under some questionable, idiosyncratic interpretation of copyright where calling an external library function somehow makes an independently-developed module containing no kernel code a derivative work of the kernel is not one of them.