Based on the image you provided, I understand that you want to remove the information(orange one)from a specific meeting room.
After my testing, the information is a mail tip on the meeting room. As shown in the following figure.
You can disable mail tips for the meeting room with the following command: set-mailbox -identity -mailtip $null, the result is shown below. Details can be found at https://learn.microsoft.com/en-us/powershell/module/exchange/set-mailbox?view=exchange-ps
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