It is true that local events can influence trip planning, but their role is not always a decisive and systematic component of destination validation.
The idea that they are always at the heart of every selection process is a bit strong; it is rather a contextual consideration.
In Dakar, for example, the Tivaouane Gamou is a major event that affects transportation and accommodation in the Thiès region, but will have little direct impact if you plan a business trip to Toubab Dialaw.
Its importance varies greatly depending on the type of trip and the exact location; it is not a universal step.
Researching these events is crucial, but it is a modulable factor.