I've seen this in an alliance forum before and seen several folks make threads similar for their personal reasons, but prehaps since so much of the RP community is here and it's sometimes hard to tell everyone what's up - maybe a stickied, "Post here if your going away for a few weeks and don't want people to wonder where ya went" thread.
I figured if the idea was liked it was best started by a moderator and made official and such.