>Didn't the calendar say this would be on the 27th for a time or did I misremember it?
You remember correctly - it was originally scheduled for the 20th, then kaguya realized he probably wouldn't make it so it was delayed 1 week to the 27th (and later streams were shuffled a bit to avoid any overly short/long gaps, and to adjust for Bunkasai and Halloween)

Then I found out I wouldn't be able to make the new June CyTube date, but would have been able to make the old one - which is a bit more of an issue since I'm usually the one who prepares the files. So yesterday kaguya moved it back to the 20th and announced it - gomennasai

To be honest, I didn't think anyone looked at the calendar ( https://cgi.heyuri.net/calendar/ ) since we often get asked about when upcoming events are happening despite it all being there