Ironic, because on one occasion when Pirlo looked right to pass to Elia in the wide open space on the right Elia was stood in the centre forward position with two defenders on him
or that time when he found elia there.

this is my whole point
why do you think most teams suck in pre season because they try to know each other. Elia missed the pre season games.
and that makes it harder to get to know where he likes to walk and how he likes to play and where conte/pirlo likes him to play.
Take the the problems he had with the languages and adapting and you have the reason pepe is playing all the time.
The situation you described normally happens in pre season and not during league games. And if they play games or have time to practice during the season with the whole squad the starters are on international breaks.
Italian football is very tactical so it is very important to know what people wants from you and what your strong points are.
Clearly the team is more used to play with pepe and not with elia. What a surprise Pepe was here last season, was here in pre season and talks Italian and knows the serie A.
It is easy to bash elia for walking wrong but you have to admit it is hard to get in a team and know 100% where to walk and what to do if you never play with them?