I believe Macaw.casino is one of the first gambling services that will have a sign up-less feature, https://bitcointalk.org/index.php?topic=5405538.0

The casino requires the user to make an account for now, but of their schedule of new features are on time, it will be removed and the casino will run everything on top of the Lightning Network. THIS is the ACTUAL point when I opened this topic.

Our questions will be answered when sign up-less feature, and no-KYC are implemented.