It has been known for quite some time that the project was behind. There are too many custom finishes with the lighting, HVAC, and general appearance for that to be a surprise. The supply chain issues in the trades were very much a 2021 and 2022 problem. That isn't a huge problem anymore, but here is what is: Having enough skilled tradesmen that understand what they are installing. For example, the average journeyman electrician isn't going to have any experience or exposure to the types of custom lights and controls that are engineered into the project. Same goes for the average mechanical journeyman. That shit takes time, and you really only get one shot to install something that isn't repetitive, otherwise you have to rip it out and try again. Just venturing to guess this is happening a lot.
In regard to Rhule's input, other than minor finishes and decor, I would be very surprised if he had any input at all. Major changes would require architect and engineering changes...many of those plans were stamped in 2020. By the time Ruhle was hired, much of the general rough-in was complete, so structurally it seems very unlikely. It seems more likely, IMO, that was a rumor or series of rumors by the general contractor (who is a close friend of Frost) to create excuses for the delayed timeline for completion.