This term has it's place for me for I certainly have weird dysphoric experiences when I'm regressed. However, because this whole thing is is so confusingly intertwined with the physical reality of actually being an adult, and the necessity to function and survive in the world, I have, like most regressive ABs I guess, developed the ability to cope with physical reality most of the time while learning to suspend disbelief when regressing.
So back to dysphoria. Well, I know that for some, there is a serious psychological disorder where the person simply cannot accept their physical condition ... being trapped in the wrong body etc... it's definitely not that bad for me, but I'm starting to get sadder as I think about getting older, like while I can still look kinda boyish it's not too bad, but I'm not sure how I'll be feeling when that goes.
The awesome thing about regression is that feelings and thoughts can almost completely override any sense of physical reality ... it's only occasionally where I might for example notice my hairy arm when I'm deeply regressed, that I might be slightly startled. Mostly though, since my body has developed concurrently with my little self always there, it's more of a happy symbiotic relationship, each side respectful of the other.
Mostly rather than dysphoria, it is a sad lament for a body that is no longer there. I so wish that I was small enough to curl up on my partners lap...sigh. It is extraordinary how diapers and other paraphernalia can assist with suspension of disbelief. I think that has a lot to do with transposing adult physical sensations with familiarly infantile ones.