Rotating the tires in itself can't cause the problem and it's possible that whoever rotated them, perhaps a kid (a "lube tech" or trainee, not a Volvo master tech who should know) wouldn't know anything about the AWD tire problem. I do see your point there but I also think it'll be hard to point the finger of blame on that dealer for failing to inform you about the different sized tires that you previously had installed.
It's also not any dealer personelles job to send out any service bulletins or tech-net notes. Whoever told you that was wrong. The ONLY time that Volvo cars or VCNA (never dealers) sends out any literature to Volvo owners regarding service work is when there's either a campaign or recall and none of which apply to the AWD problems.