Fantastic POV shift, it does bother me when the narrative for the Silm assumes things that could not possibly have been known without 'insider info'.  

....he is so hurt still, and sees nothing in Valinor for himself if he leaves Námo's halls. Every point he makes puts such an interesting turn on the events. That no one on the outside of Mandos would believe him or welcome him is tragic. Because he deserves a better life as much as any of the Kinslayers. 🖤

It's true, this is one of those gaps in the Silm, if you read it as a history (as I do), where you have to wonder -- how did they know? Interesting exploration of that what if!
Whatever others actually thought of him, or believed they thought, I can't imagine Maeglin ever felt at ease in Gondolin; and given the manner of his arrival, and losing both parents almost immediately, I can understand why.