The Comiket 95 catalogue is out, and BUTAOTOME are there!
December 30 (Sunday, second day), booth 東シ78b

“We look forward to prepare new albums.”

We definitely get the usual Touhou vocal album and Nekokenban 17, but who knows if there will be a third thing!
Apparently the realization has already started and the Sis doesn’t have any problem to spoil stuff in her livestreams. On this screenshot you can read “winter cover Seija” (冬ジャケ正邪) as the filename.