No, gender dysphoria is not necessary to be non-binary, because to be non-binary does not imply that one has to be suffering from a problmatic self-concept or conflicted identity. Many people think that being transgender, for instance, is the same as having gender dysphoria, but that is not true, in fact, being transgender is not even considered a medical condition, the only reason it is still included in some medical classifications like te DSM or ICD is so that transgender individuals will be able to get insurance covered therapy or medical procedures.