That's old and very outdated information. He was a "consultant" back when it was first announced, but this was before a finalized plan was settled on. His ideas I believe were ignored. In a podcast he went on early on in Tiana's construction (mid 2023), it was abundantly clear that he hadn't been involved in ages. He noted that the ride required tension and threats in the storyline to work with the drops and their buildup. So it's clear that he was aware of the basic ideas they had settled on and was not subtle about his harsh criticism of it. He also heaped praise on Tokyo for not getting rid of their Splash.
He was always against them getting rid of Splash. In the aforementioned podcast he was quite scathing about his disdain towards those who supported its removal. That said, he had likely hoped to positively influence the direction of its replacemement, so he was initially willing to be involved in an attempt to try and steer it in a better direction. This did not last long however as all of his ideas were very clearly ignored.
In hindsight, Tony was likely made a bunch of intentionally false promises by leadership about what sort of involvement and control he would be allowed in order to convince him to put out a public statement of advocacy on behalf of the project. He has a lot of clout and respect within the community. There's a good chance they never had any real intention of doing anything he wanted and threw him under the bus soon after.
That said, before it was actually announced, the project in its earliest forms WAS likely conceptualized as a straightforward book report of the film. It's the easiet thing to come up with quickly. That is probably the idea that Tony saw and thought had the most potential, since there was a better chance of it maintaining its darker moments and also a villain. I had also heard early on that they would be keeping a lot of the original America Sings AA's at least at DL (and in my defense, I think Splash Archive also heard that there were internal battles to keep some of them as well).
It came to be known after its announcement that the ride would take place after the film. Tony probably wasn't particularly in the loop anymore around this point (if he ever really was), and likely departed not too long after he did his PR statement when they began to ignore his ideas. Jim Hill I believe was one of the earlier people who reported on the storyline being post-movie, saying that Louis would lose his trumpet and needed to find it before a big party. With most if not all characters being scrapped and being a mostly video-projected affair through empty unthemed environments (much moreso than the end product). This would seemingly have been a cheaper budget, something like $30-$40 million.
It does sound like the Lost Trumpet idea sort of evolved into the version we ended up getting, though with a significantly higher budget (I recall someone claiming around $140 million or so but I forget where) and no longer being as Louis focused. Even later in development however, there seemed to be changes to certain scenes. The piece of art with Tiana and Naveen in a small boat was nowhere to be seen in the ride, despite that being released alongside the model at D23 not long before Splash closed. Splash Archive said it was going to be located in the former Laughing Place at Disneyland (where the dog animatronic was, repurposing his boat). Naveen only appears the one time in the finale.