I have updated the following page with more information, and a suggestion that if any team/individual is interested in organizing/hosting Wikimania in 2018 or 2019 that they get in touch with me by November 10, 2016 and also indicate their interest on this page:
Thanks, Ellie
PS Thanks to all who have already come forward. The Steering committee and WMF will be updating status and recommendations as we go forward in the coming month.
Ellie Young
Events Manager
Wikimedia Foundation