TL;DR: it does not affect NVIDIA driver users on the desktop. If you’re one of those, don’t worry, it doesn’t affect you.
What the change actually does: It makes it impossible for a networking driver to integrate into the NVIDIA driver P2P interface (for RDMA) without having a complex install where the networking driver has to depend on the NVIDIA one. symbol_get() allowed for that integration to be done seamlessly, regardless of if whether NVIDIA drivers were actually installed.
Making get_symbols() only work on EXPORT_SYMBOL_GPL symbols is bogus in that case. And yes, a number of the networking drivers that I’m talking about are dual GPL and MIT licensed.
And that’s all about it…