When creating an online meeting through the Graph API (beta) for a team channel, there is no way currently to associate the meeting with an Outlook Calendar event for the group/channel.
Therefore, when starting the channel meeting and recording it, Teams ignores the Subject of the meeting and displays the title 'Meeting in "General"' instead of the subject of the meeting provided via the Graph. The resulting recording is then prefixed with "Meeting in _General_" instead of the name of the meeting created via the API. Presumably because there is no calendar event associated to these online meetings.
This means that users who create Teams meetings through applications using this API will have to rename their meeting recordings for each meeting, which makes it difficult to organize the recordings for each meeting.
It would be nice to have these channel meetings created via the Graph API work more like meetings scheduled form the Team channel as it would drive more adoption of this API and open up possibilities for connected applications to use these features.