This bug was logged yesterday. It seems like something that should be tested more thoroughly!
BUG-000130643 - XY Table to Point in ArcGIS Pro 2.5 does not retain the number of length for the text field from the file geodatabase table in the output point feature attribute table.
I broke my usual rule of not installing .0 versions of ESRI software!
I think I may have misspoke adding to this thread. It appears that I encountered this bug using the XYTabletoPoint, not displayXY. When I noticed that 2.5.1 was released and fixed the 'ToolValidator' object has no attribute 'isLicensed' bug I immediately downloaded it and reran my script. It worked! I assume both commands were hitting the same bug.
Not only that I can run the script in my IDE instead of just as an ArcGIS tool. Happy days.
Yes there is a list of bug fixes:
Fiona - in reviewing the internals I see that the bug listed in not yet fixed in AGP 2.5.1 nor is it listed in our AGP 2.5.x Release Notes I did a search for XY in the Release Notes and found 1 occurrence for a somewhat related BUG in the sense it had to do with the XY Table to Point. Those details are "BUG-000128741 - The XY Table to Point tool fails when the input table has fields with special characters in the names, such as Lat (degree symbol) and Long (degree symbol)."
I don't have the 2.6 AGP Help doc yet as it's not yet released.