I have upgraded the SX20, MX700 firmware to CE8.2.2 and it's not showing the status on screen as "Room available all day".
Any setting or this is discontinued, Devices are added on TMS as well.
The message should still appear in CE8.2.2.
If you have a custom wallpaper uploaded to your endpoint, then the message is disabled.
What was the previous software version you were running? Have you tried to perform a factory reset to see if that brings back the meeting information on the screen?
Previous version was TC7.3.7 and to let you know if any meeting is scheduled on TMS and this endpoint as participant then it shows the meeting status on screen.
However if in a day there is no meeting then it does not show " Room available all day" message.
After upgrade I haven't tried factory reset.