It's understandable to see how the later military strikes might seem connected, but Polymarket resolutions for specific dates usually depend on events during those dates.
Perhaps it's more that the markets for June 19th and 20th resolved as 'No' simply because no action occurred on those days, rather than being triggered by something that happened later on June 21st.
It may be that the market's timeframe itself is the most important factor here, similar to how a document deadline means a form is incomplete if not submitted on time, regardless of what paperwork comes in afterward.
Worth considering how the timing of the actual event dictates the outcome for these kinds of specific predictions.