ArcGIS Pro 2.9.12; Oracle 18c 10.7.1 EGDB:
I have a linear referencing Route Event Layer in the Contents pane. I've given the layer an alias (in the feature layer, not in the geodatabase): "route event layer alias".
In the Contents pane —> List Data By Source tab, the layer's alias is shown, which I think is expected.

Idea:
After the layer name/alias, show the layer's table name in brackets:
route event layer alias (INFRASTR.LC_EVENTS)
That would allow me to easily see what the underlying data source is for each layer without going into the layer Properties —> Source.