In ArcMap, if I have a layer for which I need to change the data source, the "Change Data Source" UI in ArcMap allows me to define a new data source, should it not already exist.
In Pro, no such ability exists. The folder or database connection must already exist as part of the project. What if it's a folder that I don't use a lot? Temporary external hard drive (which is a very frequent situation when we're mapping large incidents)?
In addition, in Arc, I can change the datasource to be a point, line, or poly. In Pro, if I'm changing the datasource of a point layer, I can only specify other point layers. Rare, but I do have situations where I change a poly data source to a line data source. Wonder why this functionality was remove in Pro?