I think Ancelotti is worried about the sort of performance Bernard put in at West Ham. He hooked him at half time and he hasn't really trusted him since then.
At one level it's a shame, as I like him a lot and he's added more end product but it's hard to argue with the manager. Maybe he is trying to send a message to the squad. I don't think we can discount that at this stage. That he's trying to set standards of what he wants and if players miss them, being quite strict with it for next season. It was interesting to see Delph dropped too, so it seems nobody is immune to it.
As for Sigurdsson, he's now a bit of a whipping boy and was always going to be post Liverpool at Anfield. I was never his biggest fan, but I can see what he brings. Especially without Digne in the team, quality balls from set plays would be one aspect of what he has. He's also 6 ft plus to helps us with height in the team. He's positionally ok without the ball. Not perfect and perhaps he gets moved on, but I can see sense in the decision.
Bernard will have to have less quiet games for me. I think we have to see the Newcastle at home Bernard 7 or 8 times out of 10. If a spell in and out of the team leads to that at the end result, then it will have been worth it.