To be frank, I think Niceklodeon deserves some blame too. I've found their episode schedules for FOP are horrific and focused too much on 'five new episodes in one week!' and then none for weeks. I'll admit I don't check regularly but jeez, I'd be more inclined to tune in if they had a traditional weekly schedule like most Cartoon Network programs or Nick's own TMNT.
I think a lot of people are getting way too worried about a character who's so far only appeared in one episode. We might never hear from here again, ever, and Tootie and Trixie could both show back up and restore status quo. She can also show back up as a non-love interest and potentially become say, a friend for Tootie or something. We'll see what happens.