You're probably right, and I don't think it's really likely, especially considering how Tsukada/Fourze's team was told they couldn't do a team up show like Decade.
Were they
told that? I recall reading the statement translated more like, "Well, we didn't want to do another team-up show like Decade, but..."
Still, I just fear someone at Toei giving Utsunomiya another chance at a crossover tv show based on the good fan response to Gokaiger, presumably assuming that it underperformed in ratings due to Sentai's own audience.
To me it seems the show that's happening because of the strong fan response to Gokaiger is Akibaranger, which Utsunomiya has no involvement in (as far as I know). Part of me wonders if Arakawa and Utsunomiya may have had problems getting along during Gokaiger... there's a real tension in the show, it seems to be fighting itself at points. Akibaranger is far less conflicted.
I think something like that, if he took his approach to tv crossovers to Rider (and it likely failing to appeal yet again to general audiences), could just end up hurting the chances of any future crossovers outside of movies...
I'd wait and see what Fourze's ending is like. If we're going to see team-ups in a show, then I could see it being part of Fourze's season ender, sort of an homage to the Showa tradition of all the Riders showing up toward the end.
As for a regular crossover series... well, it's just a matter of what Toei wants to do. Back in the day, the crossovers were in part to promote merchandise of older Riders who were still a bit more popular than the new guy. Merchandise for new Riders does so well these days, I'd wonder if Bandai would really want the camera time split among a bunch of different properties? It made sense when Decade did it, but W and OOO have wildly exceeded Decade's merchandise numbers while focusing entirely on the new property (in the TV show, anyway).