Why do universities announce interviewees for positions as lates as possible?
The people who are interviewing for these positions have existing, usually high level, positions at other universities, and care greatly about not having their current employer know that they are looking for other opportunities, to the extent that this can be helped. So the interviewing institutions do the best they can to keep the shortlist candidates’ identity hidden for as long as practically possible.

Thus, balancing out this need for secrecy with other practical considerations leads to the practice you are describing.