Maybe those discussions about DLSS are a bit overpresented, but it is not about upscaling, even it could be used to save fps.
But it is just the point that all those new AA methods coming along in parallel with the upscalers and so finally it is an EASY way now to activate much better AA in AC. Thats all.
There is no critical part in it. Some post sound like the PC will explode after switching to some new stuff.
Its just that easy: Turn on extraFX (it just must be on, no component needs to be running), switch on a certain method in the upscaling section and set the resolution (mostly 100% if you just want AA and no loss of resolution) and switch off MSAA.
In the newest dev version of CSP you can even activate more of those "scaling" methods like GSR2 and other without caring about what it actually is. And because everything is switched live you can directly try it while the game is running, so a very fast seak and find thing.
So now with the latest CSP you can easily hop on a better AA without any struggle to install 3rd party stuff. Its a thing of some seconds and it will work, If you don't care and everything is fine, you don't need to try it. But i guess all of us see those jaggy lines and Moiré patterns with MSAA and now you can avoid this if this bothers you...