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!
SuphatraChris Pepper commented
Can we have the option to see a pane that is *just * Favorited channels? they could be prefixed with the team, but I'm part of 5 teams, I care about 2 channels in each and between the unbolded text and the big icons I feel even my Favorited channels are lost in the noise, I *like* the ability to view channels in a team structure, but *most* of the time I want to just see a flat list of conversations i'm following.