This has actually been their policy for a long time now. When I started SLBoutique, I talked to Robin, and I basically... well... had to do what they're saying they're doing now. This is nothing new, for those who have been paying attention to trademark / fair use all along.
They're definitely expanding their branding, but this actually should have been done years ago. I've had a ton of t-shirt designs rejected in the past - can't say I blame 'em, given my sense of humor.
Regards,
-Flip