From my own experience with trans people, at least anecdotally, I have basically never come across someone who, in the old-school terminology, 'transitioned' in some way (i.e. at least full time transition), who didn't have gender dysphoria. This is not surprising, given the high social costs still associated with socially transitioning.

Given that 'trans rights' (e.g. employment rights, documentation rights, other anti-discrimination rights) are most relevant to those who actually socially transition (who hence need those protections to function in life), I think, when talking about 'trans people' in the context of a debate about 'trans rights', we are generally referring to people with dysphoria.