The Polymarket's resolution for June 19th and 20th resolving as 'No outcome' isn't really "triggered" by a later event, but rather reflects a deeper structural truth about prediction markets.
Their inherent design means that if an event doesn't occur on a specified date, the outcome for that date will inevitably resolve as 'No', regardless of what transpires days later.
This isn't about one event causing another; it's about the secular arc of how these platforms function over a given timeframe.
For instance, if a market is set for "Will it rain on Tuesday?", and it doesn't, that 'No' is determined by Tuesday's weather, not by a storm that happens on Friday.