If you look at it from the perspective of change then below are the contracts awarded last year -
Test Match
James Anderson (Lancashire), Jofra Archer (Sussex), Jonny Bairstow (Yorkshire), Stuart Broad (Nottinghamshire), Rory Burns (Surrey), Jos Buttler (Lancashire), Sam Curran (Surrey), Joe Root (Yorkshire), Ben Stokes (Durham), Chris Woakes (Warwickshire).
ODI / T20
Moeen Ali (Worcestershire), Jofra Archer (Sussex), Jonny Bairstow (Yorkshire), Jos Buttler (Lancashire), Joe Denly (Kent), Eoin Morgan (Middlesex), Adil Rashid (Yorkshire), Joe Root (Yorkshire), Jason Roy (Surrey), Ben Stokes (Durham), Chris Woakes (Warwickshire), Mark Wood (Durham).
Incremental
Tom Curran (Surrey), Jack Leach (Somerset)
So Foakes didn't have one and hasn't played.
Malan has mainly played T20 regularly so was only really going to get an incremental.
Wood had a White ball before so why increase it when he isn't really going to play more games as they manage him.
Curran moves into Denly's spot
Billings is probably unlucky not to get an incremental contract TBH
Crawley, Pope and Sibley all get Test contracts for the first time as they are the future. Plus Bairstow losing his frees up a contract.
Bess getting an incremental due to him being our 1st choice spinner all summer but not a Test contract because he's not the finished article yet.