Cheap reveal, only letting us know now that Wilson hasn't spoken with Amber since the day before.

I think the opposite. I only got that the necklace was made out of amber because of Jurassic Park and the mosquito being preserved in amber in that movie - there are people on the boards who didn't know Jurassic Park and didn't know the necklace was made of amber until House said it. So I can't see how that can have been too obvious, yet Wilson randomly announcing, "Hey I called my girlfriend she didn't call me back that's weird" wouldn't be hugely obvious?