Just checked out today, will likely put together a more thorough review if I am not too lazy. Here are some more detailed comments regarding the availability with insights from the front desk.

• Dec 2026 opened up at ~8am JST today per the front desk. I then verified about 30 mins later via a search and confirmed Dec 2026 was open. I didn't see any availability for Christmas till New Years Eve, either that was fully booked in 30 mins or even with December open, they hold back availability for those dates. I suspect the latter.
• The front desk then informed me that they would be doing a subsequent release later in the day for the rest of the peak season. At ~8:30am JST I checked and January dates were not open.
• Around 10AM JST, January - February (including dates for Chinese New Years) opened as previous users have reported.