Phrase request: indicator for undesired outcome

Solution 1:

You could say such a situation is ominous.

giving the worrying impression that something bad is going to happen; threateningly inauspicious.

Lexico

(Inauspicious means that probably won't be successful)

The fact that you haven't heard from them yet is ominous.

It comes from the same root as 'omen', which is often a bad thing. You'd more often get an ill omen than a good one.

Solution 2:

bad omen

An omen is something that you take as a sign of something to come. A bad omen is something that you take as a sign of something to come that's bad.

The fact that you haven't heard from them yet is a bad omen.

Solution 3:

The word "unpropitious" comes to my mind -

Unpropitious

: (of a circumstance) not giving or indicating a good chance of success; unfavorable.

(Oxford (now Lexico))

Therefore -

The fact that you haven't heard from them yet is unpropitious.

The fact that you haven't heard from the interviewers (yet) is that you probably did not have a good chance of getting selected, so no success.