Her profile in the official Dearly Stars website says she has "a big secret" and lately a lot of artists assume that secret is her being a boy. As far as I know it's not official yet, but her CV is the same as Renton Thurston's and it seems she has played other boy roles too.
I think images where Ryou is clearly a boy should be tagged trap and/or male, when it's unclear it should be just androgynous and when the artist has clearly intended her to be female, there shouldn't be any of those tags. I don't think they should have the genderswap tag either, because it still isn't official.
This image, for example, deserves the tag androgynous, but not trap or male tags until her gender is confirmed. Mayby it should be tagged possible_trap or something?
If you have ID of NicoNico-Douga, see http://www.nicovideo.jp/watch/1247262110 . In this PV, Ryo says γη·γ γ£γ¦γγ¨γγγ°γγ‘γγγγο½γ orz