Now, now, let's not forget that unlike other vloggers this is actually his job. He is paid by Thorpe Park to make videos about their park and the building of The Jack Silkcut: The Ride, they will have ultimate creative and editorial control. I'm struggling to think of any brand, or company, that would include negative criticism in their own promotional video.
This does demonstrate that vloggers/influencers need to make their relationships with the products, services and companies they're showcasing explicitly clear. In Jack's case, specifically, there's bound to be confusion as he's switched from a homegrown enthusiast (making videos for fun) to corporate shill, but is still using the same delivery channels. He may, at one time, have declared the switch; but if you missed it, or are just coming across him, his financial relationship with Thorpe Park isn't explicitly clear.
If a park has given you a gift, declare it. If a park is paying you, declare it. If a park has organised, or facilitated, a filming request (ride footage, behind the scenes, interviews, etc), declare it.