I would say yes, the meat does get softer. Don't know about down south, but from early spring or late fall and winter in Ohio, it is much more firm. Summer meat kinda falls apart once it is unthawed.
Bluegill meat seems to stay pretty solid thru out all seasons.... I tell my 4yr old boy it's chicken and he buys it........ :D:D:D He says he doesn't like fish.