It isn't that case that it could mean anything princesdando.
It definitely, at the very least, means that the applicant is not out of the running for an offer. Tutors don't send definite 'noes' around for other tutors to look at. That would be absolutely pointless and a big waste of everyone's time.
In the vast majority of cases it means that the applicant hasn't made the top cut at their college of choice or allocation, but the tutors think that they are good enough for a place if enough places are available. so, 'Oxford standard'.
In a smaller number of cases applicants are sent between colleges so that college #2 can see the standard of applicant that college #1 has in its cohort: 'standardization'. These will tend to be the stronger applicants.
Obviously this is only relevant for the subjects which pool, not for those subjects (sciences) where interviews at two colleges are standard.