Game details in assignment notice
Referees need to see the game details to know if they need to look at the game faster. If they see the game is in the next few days, they know to login immediately confirm. If it's just the normal informationless indication that doesn't convey an urgent need to login right away, that makes extra work for the assignor chasing them to reply.
The previous reason for declining this at https://horizonwebref.uservoice.com/forums/66397-feature-requests/suggestions/1536029-have-the-game-details-in-the-email-that-is-sent-ou was poor. This should be a group setting decision based on what the group thinks is best for their needs.