Shouldn't this be removed now, as SFF.SE is no longer in beta?
That page in the help centre isn't editable even by mods. Removing the irrelevant link would require an SE employee.
Also, the "How to Ask in Private Beta" link seems to be on every SE site, even Stack Overflow. So removing it would be a system-wide change which should be requested on Meta Stack Exchange. Edit: it already was requested two years ago, with so far zero response from SE employees. So there's not much point in posting a duplicate there either. (Thanks @Null for the link!)
Yes, it should be removed, but discussing it here won't achieve anything.