After doing a little web research, I'll conclude that it's impossible to know from the outside what the restrictions are on ARM architectural licensees other than they have to pass the ARM compatibility test suite. New instructions (probably not), new modes (looks like), dunno (definitely).

However, Apple is one of the founding ARM partners and it is rumored they have a special license (not all licenses are created equal). Clearly they are doing this mode thing. Whether Samsung could get away with the exact same thing is a good question. I'm going to guess that NVidia can.