The important questions would be:
- Why?
Looks like some people prefer markup, pictures, etc to plain-text communication. I don't get it (and would leave any mailing list allowing this instantly), but indeed, the forums can offer that. Then, running -CURRENT can sometimes be necessary for desktops with hardware still unsupported in any stable/release branch.
- Why not?
Well, this is still mostly a "support forum", and support for -CURRENT mostly doesn't make sense (see exception above). Discussions around -CURRENT often take a direction to "bug hunting", and having this partially on the forums would do harm, because it really should be in a central place (the mailing list) to help the developers. Of course you can't do anything about Reddit 
I could see a use for a current-14, a current-15...
A solution found in a current subforum might compel users to switch from
linux to bsd, providing us more developers.
Those current discussions not about bug hunting, could, for example,
take the form of feature rollouts
Some advanced bsd users who run current might post often enough to
gain additional experience to become developers, something bsd is short
of..
Users would no longer post about current and have to be reminded in the
usual forum subreddits.
Persons browsing -current-14 etc would * gain advance knowledge of
features or bugs, enabling greater community advance warning or
knowledge of version-to-version precautions, etc.
... at least once in a while .