That's the thing, it only could lead to lying about other things, or doing more than just lying. It's the same logic as saying that violet video games will influence people to actually go out and steal stuff / kill people. It's only an issue once they're actually harming others, directly or indirectly.
In this case, it only affects Flatflyer, and should be resolved between them accordingly, but to the rest of us it's not an issue at all. In SkullCandy's case, him lying about his gender is about as big as an issue as Pie Crust doing it, and his art thief cases were dealth with accordingly. You can't antagonize people for what they might do.
Do I need to give, like, more examples of this happening? Because there's actual proof of this sort of stuff actually happening, so it's a pretty good idea to assume the worst in this case.
Because there's Elementalwolf, who claimed to be female for a short time and was an absolute stuff, Kitty Moonlight, who, if I remember right, claimed to be female and ended up getting banned for trolling, Skull Candy, who I've mentioned, I've seen Counter98 pretend to be female ingame a few times for god knows why...
I would point out more people but I'm too lazy to dig up the archives.