Megasonic: After having the privilege of speaking with a few industry professionals, the industry is very friendly despite the competition. I've heard stories of people from numerous different companies all meet up for dinner or drinks after spending the day working at a new amusement park. I agree that not very many parks will disclose their process like Efteling did in these videos, but I'm sure it's actually a typical thing.
Whether it's a park manager, design engineer, or PR rep, it seems like everyone in the industry has a similar philosophy where there's a bigger picture than just the business. Ideas and innovations can be shared to make rides safer, more extreme, etc. Welcoming another park to ride a certain ride type that they might potentially build could allow for guests to have a similar positive experience in a completely different region.
This practice is actually pretty common across basically any industry. Automotive companies purchase competitors' vehicles to determine the whats, hows, and whys of the new design. Parts are often swapped between vehicles to determine what works better or what feels better. In the long run, everything boils down to keeping the competition alive so everything gets better.
As for Baron, they showed a clip of the steelwork at the end of that video and I was blown away by the detail present in the part. Efteling is, as expected, going the full nine yards to make this ride one hell of an experience.