A more clued up customer ordering them. If Abellio had know about the option they would have for Anglia as seats mattered there too.But they're not needed on other AVENTRAs so why here?!
It will be intersting to see the final LNWR and C2C designs.
Also with typically lower speed running onthe SWR services optimising aerodynamics for minimising drag at higher speeds isn't really worth it as they barely get above 70 any of the time.