They might do it anyway though. I have the "all apps" subscription but it's not actually everything they make any more, all their "Substance 3D" tools are another $50/mo. I can easily see this feature getting most of its functionality locked behind that extra subscription the way Illustrator's new 3d tools just give you a tiny handful of materials without that.
Oh for sure, their implementation is slicks and they're somewhat of a monopolist. The whole "free to educational institutions" really worked well for them and MS.
I don't doubt they will put prices up, just boring they don't need to.