I really dpubt Glock will make a 33+ round mag for .30SC. They haven't even made an equivalent in .40SW.
Eh, why would they? They made the 33 round mags for the Glock 18. The fact the mags fit all the other 9mm double stacks is just a happy bonus. Glock never made full auto versions of the larger calibers, so they had no real need to make extended mags for the .40's or .45's.
Beretta and HK are the only gun makers I can think of off the top of my head to make a tacticool PCC chambered in .40 or .45ACP too for a long time. The Marlin Camp carbines might've been offered in .40, but I'm not sure. They were designed around the Smith & Wesson magazines, and so 15 rounds was as big as they got too.
.40SW isn't dead, but no one is rushing to make new .40SW designs, and .45 versions of successful 9mm's sometimes take years to come to market. Glock has had the 43 and 43X out for years, there's no .40 cal version in the works. A Glock 43X or 48 like .45ACP would probably have a good following, but they'd probably kill the Glock 36 off if they did.
.30SC is a round that - if a maker like Glock gets on board - people will probably beg for extended mags, because they'd fit most of a box of ammo in them.