Amusingly, our local group is almost the opposite. The SOP program we run has, over the years, run Call of Cthulhu variants (8? seasons), Chronicles/World of Darkness (7 seasons), Mutants & Masterminds 3E (5 seasons), Fate Core (4 seasons), Mouse Guard 2E (3 seasons), and a handful of one-season offerings including Star Wars: Edge of the Empire, Exalted 3E, The One Ring RPG, and a trio of PbtA titles (The Sprawl, Monster of the Week, and Urban Shadows).
Of those, only M&M was a d20 game, and then, barely so. There’s definitely been an undercurrent of demand for a D&D SOP, but we’ve been content to let the local D&D Adventurer’s League (and previously D&D Encounters in the 4E days) group take care of that, alongside the local Pathfinder Society people. We’d usually have 1-2 GMs running a d20 game during our daylong minicons, especially the fantasy focused summer quarterly con, Tales of the Crimson Boar, and obviously a lot of us are in home games using d20 systems not officially run by the Meetup group organization, but. . . yeah. We’re an eclectic group with unusual tastes, but I’ve really enjoyed getting to experience such a broad variety of unusual/indie games over the last several years.
That said, we did finally cave and got a group of GMs together to spin up a D&D SOP in a homebrew setting they’ve been developing over the last year. They’ve only got enough manpower to offer two tables a week, so I suspect demand is gonna vastly outstrip supply as our “forgotten” D&D fans come roaring in now that the void has been filled. Best of luck to our “A Dream, Awakened” team :)