You are definitively wrong here.Why are all of you so sure about that?
...and why, in the first place, should NV finaly implement Mac-bootscreen capabilities to the RTX-cards not wanting them to ever run in Macs? The 7,1 is not even out yet. And i strongly doubt that there will be only one breed of GPUs for those machines for their whole lifespan.
So many things estimated "dead" since there are Macs, which happily came back to life not even half a year later. We will see...
NVIDIA did not implemented Mac EFI pre-boot configuration support, but just a translation shim from UGA to GOP pre-boot configuration support that happens to work enough in a Mac to have boot screens. This is not news and was found very early on.