Is the Forum using XXMesenger

is this forum using XXMesenger ? (Y/N)

No, the this forum is using Discourse.

Thank you for your answer. May I please kindly know why?

I’m not sure how that would even work.

Maybe you should check out https://haven.xx.network which uses cMixx like xx Messenger did but is more of a community platform rather than a secure chat app like xx Messenger.