I see the supposed rejection of ROTJ’s ‘happily ever after’ as more of a reaction to ROTJ than anything else. People seem to have forgotten what a disappointment that film was, not just to many fans but to folks who were involved in the films. I’m pretty sure that’s why the comics had Luke turn to the Dark Side in the 90s, or why we have a ‘disillusioned Luke in exile’ in TFA with Han having his long overdue death scene. Not everyone left the 1983 Ewok party feeling satisfied. I’m more than happy to see ROTJ as ‘a’ victory and not necessarily ‘the’ victory.
I kinda get what you mean, especially when you consider that it wasn’t until the PT’s ‘chosen one bringing balance to the force’ decontextualization that ROTJ really became the final word in a grand saga. The OT, taken on its on, it’s not unreasonable that there’d be something after.