Not just the dev team but even the "product owner" gets blind sided in "small" and "agile" companies.
The CEO or someone high up the food chain sees a defect and now zomg the sky is falling.
It has to be fixed nao, prioritization be damned.
That's what I meant by nobody from the above list can be a product owner.
The whole point of having sprints is so things can't be added to a sprint mid-sprint.
Maybe there are extenuating circumstances but they should a. really be extenuating circumstances and b. should come through the (clearly nominal) product owner.
In the companies I work at we can create whatever ceremony our team deems nessesary as long as we're meeting our metrics.