I think it can be, if the delay in a timely closing can be tied to the borrower.
For example, IMO only, closing is delayed because the appraiser took their sweet time to schedule and complete the appraisal, then no, that is the bank's issue for having a lackluster appraiser. If the borrower failed to get back to the appraiser to schedule an appointment in a timely manner, or the borrower made it difficult in anyway to get the appraiser into their home in a timely manner, then I say it is the borrower's fault for the delay, and could be a valid changed circumstance.
As the FAQs state. "The particular facts of each situation must be examined to determine if the facts constitute a changed circumstance."