Judging by the aerials they're either precast pieces that are just going to show up one day or they've been cut due to how close the treeline is to the track. Given how critical of a pivot point this seems to be in the storyboard of the ride, I'd imagine they'd need some kind of alternative to get us into the show building.
Also, I know a lot of you have questions regarding the mechanics/safety of the track switch so here's a great video mounted to the rear of a train from a roller coaster in China. It shows the same style of track switch that will be used on Potter Coaster. Here's a couple of things to consider when watching:
1. You'll notice how quickly the track pivots/locks into place. Home position on a track switch like this is actually the straight piece. Curved piece is considered a transfer.
2. In the instance of a power failure or a track switch failure, the LSMs will not be able to advance a train into launch sequence. "Home mode" on LSMs always slow down a train. It'd take an entire football team to try and manually push a train thru one of these magnets.
3. On future coasters coming out from Intamin (Parc Asterix) you'll find that the train has enough forward track to automatically advance the train without having to stop. I'm not sure if Potter will feature this or the stopping element but I don't think it makes much of a different in terms of ride quality.
4. Yes LSM fins naturally hiss like that.
