Which term describes a situation where a passenger's seat is upgraded or downgraded involuntarily?

The term that describes a situation where a passenger's seat is involuntarily upgraded or downgraded is commonly referred to as "involuntary." This situation can occur due to various reasons such as overbooking, aircraft downgrades, or operational necessities. In the context of aviation terms, "INVOL" directly corresponds to involuntary actions regarding passenger seating.

In operational terminology, involuntary seat changes often arise in the context of passenger management where airlines must adjust seating arrangements unexpectedly. Such adaptations can lead to customer dissatisfaction, which is why airlines typically strive to minimize instances of involuntary seat changes when possible. The other options represent different concepts or situations in aviation but do not specifically denote involuntary adjustments to passenger seating.