Another thing to consider is that Hocker surely wants to improve his 1500m time, perhaps thinking he can break the WR in his career. It seems likely that he's already tapped out on the speed side of things and is looking at the best way to improve his overall performance. There's more to be gained by getting stronger at the 5000m. So he's focusing on improving there.
Since he's already pretty good at 5000m, where else would he get enough competition to push his 5000m time down other than DL races and the US Championships? On top of that, maybe he gets lucky and is in a slow WC final, giving him a great shot at medaling or winning with his kick.
And finally, one day he will start to lose speed and no longer be medal competitive in the 1500m. Since our 3rd guy was 5th in the Olympics, that means also not being competitive for making team USA. So he probably wants to keep the 5000m in his pocket for the future.
Everything Hocker is doing makes perfect sense to me.