There were some Smooth licences for two transmitters. There were also some areas where coverage of Smooth on FM and DAB was very similar to mediumwave. Most if not all Smooth licences were due to end IIRC this December as presumably would their maintenance agreement with Arqiva.
National analogue terrestrial licences are covered by separate legislation as to their coverage, length and when and if they need to be re-advertised. Hence the consulations when Talksport and Absolute asked to close some AM transmitter.
At the moment the Absolute licence should be re-advertised however the Govt said some months back they'd amend the legislation so that they could continue to be extended. Ofcom will just wait until that goes through Parliament.
All of the AM/MF only sites I have visited in the last five years or so have looked very scruffy and run down and it has been clear they knew they were close to end of life. Just thinking of Postwick near Norwich for one which now only has two services left. Also, nearby Brundall which has just gone silent. That has looked a bodge for a few years with temporary guy ropes holding the mast up and a slight bend in the mast. I suspect it could be some time before the sloping wire AM antennas are removed from the Manningtree mast as they are just hung on the guy cables and the site still has lots of FM and DAB on it. Foxhall (Ipswich) and Great Barton (Bury St Edmunds) Both have FM on the top of them so will still remain. Maybe those will eventually loose their insulators in the guy cables as they need renewing. The base insulator is pretty hard to change with the entire mast resting on it so will be left indefinitely I would have thought. Gunthorpe (Peterborough) is the the same.