Economics Online Seminars
I have two here to add to your list.  

Brookings Insitute

https://www.brookings.edu/events/

St. Louis Fed  Economic lowdown
(FREE)

https://www.econlowdown.org/

There is also the National Association of Business Economics (NABE)
But to get access to their webinar resources you have to register on their site.
I know this won't qualify as it is not free but they are a good source of up-to-date information.  I felt that this would be a good share. 

www.nabe.com



Others that I just found:
Peterson Institute for international Economics

https://www.piie.com/events

National Bureau of Economic Research (www.nber.org - click on videos) 
or 

https://www.nber.org/video_archives.html

Organisation for Economic Co-operation and Development (OECD)

http://video.oecd.org/

World Bank
https://www.worldbank.org/en/about/archives/past-events