On the note of manufacturer; I have changed my mind somewhat since yesterday, and I reckon there’s a good chance that Zierer could be our manufacturer here.
If I were in a speculative mood, I’d guess that Merlin may well have some kind of bulk deal with Zierer, or at very least an incredibly solid relationship with them for building Legoland coasters.
A substantial percentage of new Legoland parks are building/have built Zierer Force Five models as their Dragon coasters, Legoland Billund’s Flying Eagle was a Zierer Force, Legoland Billund’s Polar X-Plorer was a Zierer… Merlin does seem to gravitate towards Zierer quite heavily for building coasters in Legoland parks.
By comparison, Merlin doesn’t seem to have much of a relationship with Vekoma. Apart from Haunted House Monster Party, I’m struggling to think of any Merlin projects that Vekoma manufactured, and they certainly haven’t installed any Vekoma roller coasters, as far as I’m aware.
With that in mind as well as the other evidence (the track design looks very Zierer, and I also heard someone say that the airgate design looks very Zierer as well), I would not be at all surprised if this was Zierer building their first ever shuttle coaster. In fact, I’d argue it’s possibly more likely than Vekoma, in my opinion.