Who's to say it isn't the other way around? They wanted Silver to be more cutesy-dorky in the comics, so they changed the eye shape to reflect that and make him look less serious. It's not just the way he's drawn that causes that perception in the fandom, it's how Ian Flynn writes him. Silver was written and drawn to be "cuter" as far back as 2011, long before the fandom made his "smol cinnamon roll" personality popular. And if Team Sonic Racing is any indication, that personality is canon now.