I've emailed SP, and Melissa has said that they are considering topre caps. But I don't think the hobby market for topre will be large enough for them to invest so much into new molds.
It's definitely not. Yeah, the first run or two might go well (assuming they don't price a lot of people out), but after the first big colorway sets run- how many repeat buyers will there be? There's a larger barrier to entry for Topre, and not a lot of variety in the typing experience between models, so the average user just doesn't have three or four Topre keyboards sitting around that they can place sets on and feel like they are being "used" like they do with MX. It'll mostly fall back to collectors and new buyers, which can't be more than 40-50 people per run (and that's including participation from all major communities).
The only mold these companies truly need to make is a Topre-stem spacebar mold that they can use to match up with their MX sets. It's a rough solution, because it still requires MX sliders, but it's the most viable. Problem with that is that once Topre rolls out MX-compatible keyboards for their Realforce line sometime within the next year or so, demand for that mold will drop to mostly just HHKB users. And this is the real reason why we're unlikely to see any new Topre-compatible keysets from the mother company- they're leaving us behind.
You guys want to see a price dive? Just wait for those Realforce (edit- they'll like be Type Heavens) keyboards to come out, then open up r/mechmarket a few months later. It should be fun.