Option "Make newly added layers editable by default" should be "opt-in" (the default as "disabled")

[MattWilkie3]

This idea split from ArcGIS Pro: Provide an option that requires all edit sessions to be manually started  as it is a distinct idea.

Every edit session should be started deliberately, intentionally, willfully and knowingly, especially now that Pro can simultaneously edit two or more different workspaces (e.g., file GDB and SDE). Many of us have decades of ArcMap's "manual start edit session" paradigm in our operating assumptions. Although a bit inconvenient, the ArcMap approach is less dangerous and less error-prone. A significant number of new people could also stumble into this pit-fall.