I don't think that Volvo even teaches newer techs anything about MTs anymore. Not much about clutches either btw (even though a fairly simple system). Years ago, other manufacturers (like Subbie) use to teach details about R&Ring the guts of their MTs and way back in the mid 80's, I was even at a Volvo MT class too BUT in recent times, I'm not sure that Volvo teaches anything now to younger guys so obviously, how much could they know?
Volvo also doesn't teach techs much about the inner workings of automatics either YET the same techs are suppose to pass the ASE auto trans test to become a Volvo master tech these days. Volvo never did teach an auto trans overhaul class, at least not in my days. Volvo prefers that dealer techs replace their transmissions with remans which makes sense in that unless you overhaul ATs often, the odds of one missing a small detail and having it come back are great really (not worth the hassle of trying the costly and very time consuming learning curve).

See, when one drops the car off a service writer writes it up and it's then dispatched to one guy. That guy can be a "kid", lube tech, etc who knows almost nothing about your car. Being that MTs are rare these days compared to many years ago and that MTs rarely have any problems, I can understand why a Jr tech might not know much about how to properly diagnose a clutch problem but then too, your car should have then been dispatched to a more experienced tech if one exists there.
Chances are good that that dealer has at least one real tech who'ld know better but unfortunately that guy didn't get your car so you then got incorrect info.
If you ever go back to any dealership and your car needs more than an oil change or basic service, request that a Master tech only works on your car as people can do that and often do where I work.