Ask a question: Reminders not an option in topics to choose in "Ask a question" forum.
I think the title is descriptive enough. Lol even "Using the Community" is an option, which I didn't expect.
Welcome! You are correct in your observation.
There was recently a serious "pruning" of the number of forum sections, but Reminders has never had its own that I recall, and I've been here over 20 years.
Historically for macOS, built-in apps like Reminders, Notes, Mail, Contacts, etc. are best asked in the forum section for the OS version installed changes in that type of Apple app tend to run with changes to the macOS version. Therefore, I ask those in one of the forum sections listed here:
For iDevices it is different. Different iOS/iPadOS/etc. versions do not have separate forum sections. I usually recommend such posts go in the root forum section for your device.
etc
We are neither Apple nor moderators but your fellow end users, so we cannot speculative on why Apple does or does not do something.
The contact email for the moderation team is shown at least three times in the Apple Support Community Terms of Use we all signed to join here.