I hadn't noticed 'til you mentioned it... I suppose if a board host saw a message that was critical of them or tried to coax people away from their board, the tendency might well exist to delete said messages! So that might be expected. She lost a lot of trust, I think, when she seemed to do that too capriciously, so I think folks may be somewhat watchful of it... but I can't say I'd blame her for deleting those.
I recall some time back someone else posted a link to this board there, and I did, too, in answer to Tupelo's asking what it was, and I believe she allowed those to stay.