Is 48 month rule eligible after 31st December if appointment done early?

I was able to schedule an dropbox appointment on Jan 5 2022 (since I qualify under 48 month dropbox eligibility). However, the rule currently is valid until 31 Dec 2021. I’m not sure whether my appointment is valid since I booked before rule end date or is not valid since the actual appointment is after rule end date.

I was able to message usTravelDocs and they asked me to check the below link to verify where I don’t get clear information on the same

Link is missing. I would imagine that their system should be up-to-date and so if it allowed scheduling dropbox in Jan 2022, they may have extended though there is no official word as of now. State department site still shows end date as 31st Dec’2021.