ONTD is one of the communities SUP seems to actually care about, and not just for the ad revenue. It's seen (at least by SUP) as a trendy, hip community that isn't attached to fandom per se. I think SUP is attempting to reinvent LJ as a trendy hipster site, at least as far as their users outside Russia are concerned. Unlike fandom, ONTD doesn't hurt the new image they want to project, so while they aren't actively chasing fandom away, they'll never bend over backwards the same way for a community dedicated to a single fandom. (Except for Twilight, possibly. I don't think even a juggernaut like Supernatural would have the same pull)

However, fandom in general moving over will still hurt LJ in the long run. Doubly so if SUP's hopes to reinvent LJ into a trendy social media site pan out about as well as I expect they will. (i.e., end up turning LJ into Friendster rather than a Facebook for hipsters)