The budget cycle for 2024 has likely finished so orgs are moving to execute on 2024 plans.
Executives can finalize things a bit more easily when folks out of the office as the day to day a bit slower. HR / Acctg / IT also usually like doing a one off project in these spots - usually a smaller group is in loop on these things.
The week between Christmas and New Years for the quiet meetings and week after for plans to be finished up.