It appears Team Cherry didn’t account for every possible sequence of events.
Recently, the creator behind the YouTube channel Kilroy Was Here recounted his adventures in Hollow Knight: Silksong — he managed to trigger a softlock.
He opted not to free the Bell Beast; instead he headed west, farmed resources to purchase a key, and unlocked a sealed door.
Shortly after, he reached a section that looks, at first glance, impassable without a dash — but there is a solution: defeat Hornet. When she is defeated and then revives, a cocoon spawns that can be used to reach the intended platform.
Kilroy Was Here then advanced to the imprisonment sequence and ran into an issue — because the Bell Beast remained captive, Hornet was unable to escape.
Source: iXBT.games