Simple RAW for 5e V: The Disadvantage Strikes Back

[E’Tallitnics]

Proficiency versatility UACFV p.1


4th-level feature (enhances Ability Score Improvement)

"When you gain the Ability Score Improvement feature from your class, you can also replace one of your skill proficiencies with a skill proficiency offered by your class at 1st level (the proficiency you replace needn't be from the class).

This change represents one of your skills atrophying as you focus on a different skill."

A95: RAW this is okay. If you were trying to swap out a different skill and keep expertise on the new skill there’s no RAW that supports that maneuver. But this is essentially Meta Gaming Bookkeeping.