Not sure if he was opening his mouth and letting his belly rumble, but Leitch said on Radio Scotland that a return to the tier system was likely, based upon, in comparison with England, Scotland's different geography (Islands, sparsely populated in some areas, heavily populated across the central belt). However he did moot that it may not be based on local authorities anymore, highlighting that the three distinct island groups, the North West of the country, and a sprawl from the central belt up to Dundee and Aberdeen.
I think reading between the lines a tier system based local authorties may be scrapped, perhaps in favour of doing it by health board?