What do we have to do to have Fedora 25 in Esperanto?
GNOME is translated at 61% and I don't know how much on Zanata. It is possible to use Ubuntu in Esperanto, even if there is some blanks.
Is there any criteria a language needs to meet to be integrated to Fedora?
No sure if this help or if you have not read it https://fedoramagazine.org/how_we_tra...
Maybe check if the Esperanto Language Team is still alilve, and if not you may wanted revive it... https://fedoraproject.org/wiki/L10N_T...