It's due to illness. I hope the team member gets well and feels better soon! I'm glad you linked to the updated post, because I was wondering why the stream isn't on.

Darn, it looks like they updated the article with an explanation though:

Update for Jun. 18, 2026: Due to team member illness, our planned stream for today will now be combined with the Dev Update stream, currently scheduled for next week on Tuesday, June 23 at 2:30pm EDT.