I think he's been strung along and ditched - used to get another manager to commit. Probably Silva.
Acxtually think Moshiri has used both Allardyce and the reported 'number 1 target' Simeone to try ensure he gets his realistic target in early rather than having to wait until next summer.
neither of them will object to that either - lets people know simeone is potentially on the move next summer - so the likes of Chelsea etc will be sniffing soon, Allardyce got LOTS of air time and now will likely get a job off the back of it, in a way he came out of his retirement for the Everton job, notice he hasn't retired when it disappeared though, so basically looks better than coming out of retirement for a crap team like the USA etc