More info pertaining to said game in a translated interview here :
https://noisypixel.net/compile-heart-sting-announce-new-touhou-tactical-rpg-touhou-spell-carnival/(Basically pretty much the same thing as the gematsu article except not summed up)
This news kinda came out of nowhere for me, as it lacks the usual fanfare for the devs who make sure you hear about them getting the license for our favorite magical girl series. I guess this is a bit of a logical next step for the devs considering they made an impossible to misunderstand 2hu reference of sorts in their recent Neptunia release in that Shanghai Alice girl whose design is suspiciously inspired by Reimu.
Anyways, it's always nice to have something to look forward to. A proper game-like-game release is oddly refreshing compared to the various mobile games announcements.