Got this email today. Applies to older smart TVs.
On September 30th, some older smart TVs (some LG, Vizio, Hisense, and other unsupported TV platforms) will no longer be able to use secure connections to communicate with Plex Media Servers. These devices are no longer supported by their manufacturers, and won't be receiving an update needed to continue making secure connections to a personal server.
If your TV is on the same network as your Media Server, and you haven't made changes to your secure connection settings, this change should have no impact on your experience.