I often reconsider the instrument that I would like to assign to a MIDI track, and drag over the instrument to drop on the track, in either Session or Arrangement view.
I used to have the experience that Ableton would then rename the track to the name of the instrument, which I found convenient because I can see at a glance the instrument assigned to each track.
Recently though this doesn't seem to happen automatically (Ableton Live Suite 10.1.1.). Is there a way to enable this behavior again, maybe through a preference setting?