I don't think the Phillies are any more or less conservative than other teams. Surgery is always the last resort. Obviously it varies from doctor to doctor but that's also why players consult outside doctors. Seranthony went to James Andrews and he didn't advise surgery, who would get a third opinion after that?
And it's still better than being a team that forces its players to get surgery like they are a piece of property.
I would actually characterize the approach, from the team perspective, as being overly hopeful, and perhaps even overly thrifty. Once surgery happens they have lost the player and essentially wasted all the money they spent on the player (as with David Robertson) for a season or two. So in that sense they may not be in any greater rush than the player is. And the players, of course, tend to play hurt and not be honest with themselves or the team until it's too late. We saw that with Arrieta and AJ Burnett and countless other guys who pitch through things until they can't, and/or just have a bad season until they can get under the knife later. Even Eflin counts in that regard.
It's not exactly great long-term thinking. But we also don't remember all the guys who didn't have surgery (Nola being the one we do remember).
I think you keep him, and I think he'd get claimed (making the Rule 5 scenario moot, at least for the Phillies). Not gonna be hard to keep him this season, obviously.