Hi !
You are right regarding the pure multihoming.
However what I looked into was the fact, that ESI-multihoming is a kind of aggregated ethernet- MC-LAG, so a close controlled connectivity.
In this case ( this topic) the CE side is NOT a single CE but 2 separate switches without any control ( MC-LAG, VC,...)
So IMHO this setup is NOT recommended, as it lacks control on the CE side.
Think about what happens when the connection between both switches A and B is broken !
regards
alexander