I dont see an issue here, if the guides are updated, as they should
be. (email users of the Forum never see updates, of course.)
If they are not updated, they should be removed or archived from the
Forum.
Any out of date links should be removed, but external links are clearly
identified.
There are some guides that should be brought within the official
documentation - VPN is one of them. I've seen users previously citing
random blog posts as documentation. I think there is no way of dealing
with this.
--
I never presume to speak for the Qubes team.
When I comment in the mailing lists I speak for myself.