The behavior you are experiencing, where all Teams Rooms in a team are automatically invited to a channel meeting even when only one room account is selected, is not explicitly documented as a bug or expected behavior in the provided context. However, it seems to be a common issue that can occur due to how Teams handles meeting invitations for channel members.
Currently, there are no specific settings mentioned in the context that would allow you to prevent Teams from sending invites to all room accounts in a team when creating a channel meeting. It may be beneficial to provide feedback to Microsoft regarding this behavior, as it can lead to confusion and disruption, as you've noted.
For further assistance, you may want to reach out to Microsoft support or check for updates in Teams that might address this issue in the future.
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