Sure. A lack of grace when navigating class differences (=differences in behavior and preferences) could also be seen as a class marker, among other things. Feels rather "middle" under Fussell's rankings of class, but then that's where he put most boorish behavior (maybe for a good reason) and his treatment was too broad to allow for much nuance or coverage of sub-classes, tending to treat the latter as mostly people whose wealth didn't match their socialized class (again, maybe for good reason). Though maybe this whole thing was just your average, everyday "growing apart" with a bit more self-awareness and honesty about the causes than is typical. Maybe the parting from friendship was handled tactfully. Difficult to judge someone just from a post on a web forum.