Can someone tell me if flavor usually plays a large role in mafia games? And also I don't see why this reaction to the flavor claim is more likely to come from scum? is this obvious to other people?
Flavor is game dependent, just depends how the mod designed it.
It's generally considered poor mod form to make flavor too obviously correlated with roles because that can make a mass claim game-breaking. So let's say I was running OG Star Wars mafia and I gave the town the roles of Luke, Leia, Han, Chewie, Obi-Wan, Lando, Yoda, and the droids and I made the scum Darth Vader, Tarkin, and Emperor Palpatine. Well, if everyone claims scum is in trouble, even if I gave them fake claims like Admiral Ackbar or Wedge Antilles, because everyone else got real main characters and they didn't.
But there's 52 cards in a deck of cards and they're more or less of equal importance so there's plenty of fake claims to go around here and not much to be learned from flavor names IMO. The cards do have relationships to each other that could be flavor-indicative -- maybe all the 7s are masons together or something. But really, I tend to think this is like one of the least flavor-relevant games you could play.
My opinion is that scum is very happy to engage in a day 1 discussion about the merits of flavor-claiming, on either side really, because it's a great way to participate and look active without scumhunting or committing to anything. Scum is not super likely to throw out a claim willy-nilly like Shraeye did because as scum it's generally better to (A) not draw attention to yourself and (B) keep your claim options as open as possible. But there's something in mafia we call WIFOM, short for Wine in Front of Me, an allusion to
this high-water mark of American cinema.
In mafia, WIFOM means that whenever you can lay out an argument for why scum wouldn't do something, you can also make the counterargument that they would do it for exactly that reason. So maybe Shraeye threw out his fake claim early hoping for free towncred. That makes it hard to draw particularly definitive conclusions from Shraeye's behavior.
This went a lot of places, but hopefully it's helpful.