I read that as being totally separate options. The extra AoA vane is a third one. I don't know that it necessarily means better redundancy. I'd need to know how it was integrated into the overall system.
An AoA disagree light...all well and good, but unless the AoA is automatically doing something you don't want, then so what. If the stall warning goes off, and you know the conditions aren't correct for a stall, then straight up you know that there's something amiss with the AoA system. Spurious AoA can set off all sorts of warnings (stick shaker, stall calls, etc), so it will just disappear into the other noises.
Display of AoA is also an option. Useless to most people, almost all of the time. It is of use with unreliable airspeed, and you can accurately fly an approach using AoA, but you need to have been taught how, and it needs to be practiced. Unlikely.
Is even the MAX still using lights? Have they not caught up with EICAS yet?
The sequence should be...
1. AoA vane disagreement detected.
2. All automated responses to AoA frozen.
3. Master Caution (which is probably the red light)
4. AoA DISAGREE on EICAS.
5. Carry out whatever the procedure is.
