It's not a prophecy but an interpretation based on type repetition and fulfilment. i.e. history repeating itself... with established astronomical cycles providing the start timing of sequences. If there is an assassination then it will prove the interpretive methodology is correct and we are indeed in a sequence set to repeat itself. There are a lot more events in this sequence that will unfold if this event occurs.

If nothing happens then the interpretation is wrong and requires revision.

If it does happen then we have a clear idea on what to expect next.

The events that immediately precede the assassination are constitutional gymnastics in an unsuccessful attempt to remove the presiding executive from office. It seems quite clear already that the impeachment will fail and, as indicated, an assassination follows soon thereafter. This then triggers another whole set of dominoes.