Of the 31 best matches (counting GoldScorpion) we got 18 physical suits, 8 Ganbarizing forms and 5 in a weird limbo we're we've seen the design but it never turned up. I'm not sure what precedent that sets but those 8(?) missing Riders could just be Ganbarizing or something.Or they could be physical suits but turn up in weird places, like a HBV.

That's just considering all the options though - we could well get a full physical armour suit for every main Heisei Rider, which I'd prefer.

I don't think we've ever had designs in catalog scans that only ever turn up in Ganbarizing, and I don't think we've ever had HBV/special/movie forms in scans that weren't called out as such.
Though remembering the Ryuki Ridewatch comes out in five days, it is really strange. It would suck if most of Heisei Phase 1 got utterly shafted just because they can't fit them in their form debut schedule. Hopefully they can show up in Q2 in spite of the toys' release schedules.

Still disappointed they didn't tease the RD form suit for the finale to make people go see the movie in theatre instead of a lame cgi suit. Too bad incorporating next rider in movie and ending will get retcon except for rare instances like gokaigrr.

Interesting thing I just noticed, by December the RideWatch distribution (assuming Geiz keeps the watches Zi-O gives him and vice versa) appears to be pretty even:
Zi-O: Fourze, Ghost, OOO, Gaim, Double, Decade = 6
Geiz: Build, Ex-Aid, Drive, Faiz, Genm, Wizard = 6

Any ideas for a tertiary rider?

If they ever give us one since Zi-O is a metallic watch and Geiz is a sportwatch so maybe a smartwatch?

Nah that's Zi-O's Upgrade form, atleast from the scans it looks to be that Decade makes him a smartwatch.

No wonder that Decade motif power-up looked so square. I thought it was a reference to Ganbarider until you brought it up. :lolol

I think one of Time Jacker will become new Rider. Maybe Schwartz? If he become Rider, maybe his Rider name is Kamen Rider Schwartz.

I'd guess the Time Jackers either will all become Another Riders themselves or all become Riders early next year through a new belt, like the Genesis Driver Riders in Gaim or the Sclash Driver Riders in Build.