Listen, is it normal when a company just completely disappears after an interview? And what if I disappeared like that? So they’re allowed to treat a candidate as nothing, but I’m not allowed to do...

My sincere empathy for your experience by a manager that you were a candidate for a position. Appropriate manners and etiquette are certainly lacking.... Consider this a fair warning that this manager doesn't respect people and will treat you like nothing as an employee. You can call the manager's admin, or the HR person you spoke with when setting interview appointments to learn the score. This reminds me of a Sr. Executive that I assisted in his job search. He called me because he was offered a position, however, the letter defining his responsibilities and salary, the salary was incorrect. It was lower than what the hiring manager had offered him. When he talked to the manager, the manager said, "You will need to take that up with HR." I said, NO. The manager needs to handle it. This is a red flag that he won't go to bat for you if other mistakes are made that needs to be corrected by the boss. He sent the manager a letter to decline the offer.  more