Editing Templates for layers of Feature Layers are currently always edited via the Map Viewer of a Map containing the layer, but saved in the Feature Layer. So all maps containing the layer use the same Editing Template, and editing the template in one map changes the template in all other Web Maps containing the layer. The idea is to make it possible to save the Editing Template either in the Feature Layer or the Web Map, similar to how it is already possible for Forms.
This would make the following use-case possible:
Team 1 uses Web Map 1 in Field Maps to create Features in a layer of a Feature Layer. Team 2 uses Web Map 2 to create Features in the same layer. The Features have an attribute called "creator_team" and in Map 1 the Editing Template has the value "team 1" and in Map 2 the Editing Template has the value "team 2". So the field is automatically filled correctly.