I would love to see the class 221 be added to the London Euston to Milton Keynes route to complete the route,
There's currently a lot of performamce issues on this route currently due to how busy it is so we are less likely to get the avanti voyager for wcml and more likely to get the cross country variant as we have learned they now have the licencing, this would likely come with its own route and layer into many others.