I'm pretty sure all the teams had meetings for the managers to say who was impacted and communicate plans going forward. it wasn't some company-wide thing.
just one particular manager probably thought their calendar events were private and ended up scheduling two conference room mtgs as "Thursday's events" and "post notification" for Wednesday and thursday, respectively.
by the time someone noticed that Wednesday and posted it here, it was already widely believed that Thurs was the day. those meeting names were merely two more pieces of evidence pointing to thursday being it.