Ya but personally I would prefer to see Weber in the lineup. I really feel he is Streit 2.0 and we need him to get games so he can develop properly.
I imagine he'll see a lot of time on the 4th line and as a 7th d-man if the Habs decide to go that way for certain games. White's out for the foreseeable future, so a healthy lineup without him would probably look something like this:
Darche as the 13th forward, Emelin as the 7th defenseman. Maybe swap Gill and Spacek because of the history between Gill and Subban, but I think Spacek is better-suited for that 2nd pairing.
I think the team actually values Diaz more than Emelin (maybe even the players, as Gorges said he was the young d-man who impressed him the most), but given the circumstances surrounding both players it'd be easier to send Diaz to the minors.