I have applied for several jobs related to marketing and project management whose postings have been online and active for months, being reposted on Linkedin several times. These appear to be ghost listings and the company isn't actually looking to hire.
I have been contacted via phone for a quick phone screener for one of those positions recently, I was asked my availability for an interview with the hiring team which I gave, I was supposed to receive an invite in the next week and I never did. I contacted the person that called me two times making sure it was clear I was still interested in this position, only to be ghosted too.
There is absolutely no issue in letting candidates know that they changed their minds, the process is frozen, or whatever the reason is for not moving forward with the hiring process. It is however very disrespectful to candidates to cease all communications with no justification whatsoever. If this is the hiring process, I can only imaging what happens when you're already working there.