This Anime News Network report tells us that Touken Ranbu is now rising (as predicted) in the Comic Market, and it’s competing with Kantai Collection [KanColle] and Touhou.
It also said this:
Kan Colle is usually neck and neck with Touhou Project, but the analysis of dōjin registrations reveals another upset. Touhou Project fell to the fujoshi-targeted Tōken Ranbu. The mobile game is a similar format to Kantai Collection, only it stars historical swords reimagined as attractive men. Tōken Ranbu garnered 1.724 circles compared to Touhou Project’s 1,666. 
After taking hold of the majority of circles in the Comiket in the past, this report states that Touhou might lose its stronghold. From my perspective, my guts is telling me that Touhou seems to become stale. I haven’t had a grasp of the indie shooter itself, but I can sense that if the Touhou community don’t fight back with new eye-catching ideas, they’re in for a setback in succeeding Comikets in a decade’s time, and KanColle will be taking over.
Take note of this though:
myrmecoleon also published predictions for Comiket 90 based on certain series’ popularity on pixiv. myrmecoleon analyzed posts on the fan art website from November 1 to December 17. Their predictions include: […] Increase in Touhou Project circles 
I can say that if there are more Touhou circles as predicted, it can stand a chance.
On another perspective, maybe this down sign is just a fluke. Touhou’s been the king before, and it only had to fight against KanColle for the top spot. Who knows?
[1, 2] “Dōjin Circle Numbers Reveal Top Series at Comiket 89,” Anime News Network, December 29, 2015