To my mind, this is Sunak figuring out the Government needs to be more 'left' (in Tory terms) to attract moderate voters, especially those in prosperous southern areas.
It's a gamble because the populist right is so strong in his party (especially at the grass-roots level, given that most members are septuagenarian UKIP types) that it could shatter the Conservative Party 'coalition' completely. Voters tend not to support parties that are engaged in civil war.
Sunak is showing unexpected strength here. I didn't think he had the bottle. However, his party may well now smash itself. Will some desert, either to Reform or to some sort of new, populist party?