i mean its very emotional lyrically... i could debate that.. i mean i debate that the beach boys pet sounds is an emo album (listen to those lyrics and tell me they could not be written by dashboard confessional or another artist)
Emo generally refers to a sound/genre and not only lyrical content (i.e. while it may be a shortening of the word "emotional", it no longer denotes the same thing, even if there are some shared connotations). Pet Sounds may have emotional lyrics and influenced some of those artists (as it has countless across genres), but it is in no stretch of the imagination an "emo" album.
Also, in indie rock circles in the early 2000s, emo (the genre) was decidedly uncool, so I think people on the message boards wanted to make sure it really wasn't.