Webex App for web is migrating from teams.webex.com to web.webex.com. Web.webex.com is the product we're investing in as we go forward, adding features and providing fixes.
The new Webex App for web at web.webex.com has been available for some time, and has been running without issue.
The old Webex App for web at teams.webex.com has been running in parallel with the new one, but will be turned off on December 7, 2021
Yes. Any meeting join links will bring you to the correct meeting.
No. While the old Webex App for web client has historically worked with Microsoft Internet Explorer, support was officially dropped on October 5th. See Webex App | What's New — Microsoft browser support is limited to the last two major releases of Microsoft Edge.
The new Webex App for web client does not work with Microsoft Internet Explorer.