I think this needs to be put into context.
Whilst I’m not taking away anything from their achievement, there really is nothing too complex in producing something like this today from commercially available packages and some ingenuity.
We operate a significant number of Level D Full Flight Simulators but we also recently made our own trainer based on a 19 seater complete with a full size cockpit, duel controls with the correct feel, sound, visual etc all for about US$10K (excluding our time). The complex (and potentially costly) part would be getting it qualified!