I’m sure he would be !
It’s actually funny, I was thinking about this just yesterday : Zappa has, as your son so elegantly showed, one of the largest personal mythology, with all those characters, real or fiction, themes that keep coming back again and again, musical phrases that got used numerous times in such different ways that each can easily be considered a whole composition, his humor, his political views, his whole visual image…
I used to tell friends who could never get into Zappa “Well, I could suggest albums and songs, but if you wanna really know Zappa, you gotta dedicated a significant amount of your time immersing yourself with his music”. That’s how deep it goes.
And somehow that seems to be anecdotal when people talk about his music. It’s no doubt today he’s respected as a 20th century composer (not that I’m downplaying rock music, but in that regard he’s unique -other incredibly talented composers did amazing things in the confines of rock music, but Zappa is the only one I know of who got famous), but even on Zappa forums there are endless arguments about his “silliness” (one message I remember finding incredibly clever was a guy saying “so a guy who’s making poop jokes past the age of 6 is supposed to be a genius?”) getting in the way of his musical recognition.