What is the simplest expression? The idea that the impact of local events is a stable sub-part of destination validation is often too complicated; it is rather a adjustment variable.
For many, the minimum viable is to travel, and if a local event raises prices or crowds, the most economical option is to change the date or place.
It is not a systematic validation step, but a flexibility in the face of unforeseen circumstances.
For example, if the sardine festival in Portimão makes accommodation too expensive, we can simply find another coastal village where we can eat fresh fish without additional costs.