Perhaps Nvidia are writing drivers that don't conform to the guidelines Apple provide for approval? Maybe they're trying to pull a Logitech and include lots of data gathering that Apple object to. Or they're ignoring things like events from power management. Or their drivers are just shitty Mojave citizens. Or they're trying to force a Mojave equivalent of GeForce Experience to be installed with their drivers.
If Nvidia are being dicks in the face of reasonable requests, why would that be Apple's fault?
Point of clarification, the article does not mention and I have no reason to suspect that Apple broke hardware they themselves sold. In fact the article does seem to point out there is support for specific Nvidia cards that Apple sold or approved. Also I find it rather impossible to believe that Nvidia couldn't release something that would restore this ability. Would a user need to disable some security feature temporarily to be able to install it? Maybe, but that's the price you pay for unsupported hardware.
Apple got burned hard [0] by Nvidia and swore off them back around 2009. And Linux Torvald also called them out back in 2013ish IIRC. Nvidia is not a "good" company. Now people have be running things unsupported and now Apple closes that hole and they are all up in arms?
> In fact my own 15" MBP late 2013 has a GFX750, which is no longer supported according to Apple Support [1]
That support article doesn't mention the GFX 750 and I can't find any record of Apple selling a MBP with a GFX 750...
Edit:
I believe what you meant to say is you have a "NVIDIA GeForce GT 750M with 2GB of GDDR5 memory and automatic graphics switching" [0] which it appears does not support metal.
If Nvidia are being dicks in the face of reasonable requests, why would that be Apple's fault?