I have Maps version 9.69.1 running on Android 8.1. I see the following options in Maps' "Notifications" menu: Traffic, Commute, Transit, Navigation, Your contributions, People & places, Ride services, Offline maps, New on Maps.

From these, the "Your contributions" seems to have the majority of toggles that people are discussing in this thread (e.g. "Adding your photos", "Contribution ideas", "Questions about places", etc.).