It's been a couple of years since I worked at Festool, but Germany used to exclude warranty cards for U.S. tools. However sometimes they would be included. That's why you may see them in some tools but not others. In Europe, companies can require registration of a product to enable the warranty. That's unlawful in the U.S. So registration isn't required for warranty in the U.S. for any product, including Festool.
Hope that explains the warranty card situation a bit.
As mentioned, you can always register your tool on the Festool USA website in addition to relying on your dealer. That's the best way to ensure complete and accurate registration info. Having worked on the inside, I've seen where wrong or missing data existed with dealer registered tools.
Shane