The webinar will be on 16 June.

More info and link to sign-up sheet here: 

Please RSVP via this form by 10 June 2016. Remote participation details will be sent the week of 13 June 2016. The ICANN Policy Development Support Team will provide a Policy Update Webinar on Thursday, 16 June 2016 at 10:00 UTC and 19:00 UTC, in preparation for the upcoming ICANN Policy Forum...

https://www.icann.org/news/announcement-2016-06-02-en

Greg