Not final in the sense of enforced, but final in the sense of documented. Evolution is to be expected (let’s say that hybrid picking becomes more popular, etc.), but I think the techniques are done, and this is why: The left hand seems to have been mature for centuries, the right hand learned to tap like the left (at some point, I don’t know the history), picking with fingers seems to have been mature for a long time as well, and the last thing left was picking, but if one knows about the idea of “trap” and “escape” (quite profound, and I didn’t know about Gypsy Jazz, etc.), one can deduce UWPS, DWPS, 2WPS, etc. (as all of these are obvious by symmetry once one sees the first one). So, is anything left other than lots of practice and trying to find what works best for a particular musician? I doubt it… presumably conservatories can now teach metal guitar and should be able to pump out excellent instrumentalists, and people trying to play like their favorite shredders don’t have to invent anything or be lucky. I still remember when EVH came out, and how I was blown away by the tapping: I think that was the last time I saw anything “new” [not commonly known] in guitar, perhaps excluding MAB’s various techniques (like playing with crossed arms, etc., but this is of questionable musical utility). Anyway, perhaps a new technique will emerge tomorrow with a fresh guitarist, but I will be greatly surprised if that happens.