The recently added unit says
<!--T:78--> Middle-clicking an item will append it to the playlist and begin playing from the start of the playlist.
Is this new behaviour in 2.8? I have 2.7.0 installed, and when I middle-click an item it is appended to the playlist (as claimed), but the newly added item starts playing - not the beginning of the playlist.
Yes, this is a new behavior, but not described correctly: Now double click appends to the playlist but doesn't start playback to avoid interrupting what is already playing. Middle click will append AND play the added tracks, NOT the start of the playlist, that would be nonsense.
I fear that the editor has just read the ChangeLog and misunderstood (as there were some confusions among the developers as well) but didn't really try or even have 2.8, as he sadly also just edited screenshot captions, not the actual screenshots :(