For a goalie, an injury like that will take some time to heal as they do move around and put a lot of strain on their joints.
I would think Antero would be out for 2-4months after the surgery and i say 2-4 as in maybe 2-3 he'll be ready, he'll need 1 month to get back in game shape and see if his hip is 100%. I had a friend that tore his labrum and he had to sit out of hockey for 6months before he was 100% ready and this guy was in outstanding shape prior to the injury.
I don't get the dislike for Robert Esche? He has been a consistently good goaltender for the flyers since he was traded to Philly. He's never been below .500 for his record and has always had a sub 3.0 record with the team. I'm sure he'll take advantage of his role as the designated starter while Antero is out. Best case scenario is that Esche plays very well and the flyers have a solid guy to trade to a team that is struggling between the pipes.