When I was in my career transition, pursuing my next role, I was contacted for an initial phone interview by a particular organization. The time was set but unfortunately the call did not occur. When I attempted to reach out to the contact person who made the arrangements, the phone was not answered and the messages were not returned. No reasons were communicated for the abandoned appointment.
In most cases, the acceptable practice is simply to send a communication that the organization (or individual) does not wish to move forward with the application. By leaving things open, that creates some delays. Overall, ghosting may avoid conflict in the short term, but it creates additional uncertainty about perceptions and expectations.
In the particular case, I treated it as a rejection and moved on. The experience would make me hesitant to pursue future roles at the organization. It is better to simply provide timely communication, and extend best wishes to the parties involved.