Xyxox
Hero
This is already established case law. It's entirely legit for a product to make use of another company's trademarked name on its packaging for purposes of comparison or to indicate compatibility. Role-Aids did it without licensing for years and only got nailed in court when they submitted to a more restrictive license and then broke it. It also happens all the time with generic over-the-counter medicines. Look at the package for generic Ibuprofen and you'll likely see a blurb saying "Compare to the ingredients in Advil Extra Strength (TM)".
Thanks for the clarification. It does, however, limit what can be put into such products. That's the carrot of the GSL. The stick is the fact that WotC can nullify the GSL at any time.