Here are the press releases:

Japanese:
http://press.jal.co.jp/ja/release/202301/007195.html

English:
https://press.jal.co.jp/en/release/202302/007198.html

Although the title of the release says that it's about the "summer schedule," it says that during the "2023 winter season" (does that mean the current winter, or the schedule from late 2023 through early 2024?) the A350-1000 will be JAL's new flagship and will fly JFK-HND. The international cabins will supposedly be refreshed (presumably with new seats).

Within the press release there is a link to a document that details the planned flight frequency by route. What it doesn't show is equipment changes. For example, I discovered today that the DFW route will switch to a 777-300ER in March, but this is not mentioned in the PDF. Interestingly, it appears that F seats on this flight will be sold as J.