Currently we have Teams defaulted to show you the first (up to five) channels ever created. If you want to add more channels to your left rail view, just click the ellipses next to the channel name and select “Favorite”. When you favorite the channel, it will then be “pinned” to your left rail under that team name.
Try that and let me know if that meets your needs!
An error occurred while saving the commentDave commented
Another +1 on this...do not default to collapse channels. This to reduces collaboration by reducing visibility. Let the user decide which channels to pin as a favorite. Give us the choice...I am not a fan of this collapsed view off the bat.