Playlist is back in 2.1.1 : thank you !
But the 'Clear Playlist' menu has now been replaced with a 'Clear Collections' menu.
The latter command is available - as in : not greyed out - even when no collections are present.
And after some trial and error I've discovered that the only way to clear a playlist is to first choose 'Select All' and then 'Delete'.
These are not improvements, please strive for simplicity and consistency !