ArcGIS Pro 3.4.3; Oracle 19c 11.3 EGDB:
Attribute Table > right-click a field header > Custom Sort
The values in the Fields picklist are sorted alphabetically.

I can see how that would be useful in some cases for finding a field in a long list of fields.
However, I find it annoying because I'm accustomed to the table's field order and where to find a given field in a list. I set up that field ordering on purpose according to our business needs.
Could an optional checkbox be added to the Custom Sort dialog to preserve the table's field order?