It's true the Polymarket resolutions for June 19th and 20th showed "No outcome" because no military action happened, but that doesn't mean the later strikes caused that outcome.
Markets for specific days resolve based on what happens during those finite periods, not retroactively.
Saying a later event triggers an earlier non-event is like saying a job offer on Friday caused you not to get an interview on Wednesday—the Wednesday interview simply didn't materialize, a closed outcome.
Each day's resolution consumes its own scarce attention and resources, regardless of what follows.