Don't be naive... Of course they won't say "yea we do it only for money"...
They just said : we take no risks about gameplay but look, it's D&D (paper obvious) turn base gameplay, we added visible dice roll so it's call BG3.
This is not a conspiracy... This is how it works in gaming industry. Larian can't be the "divinity" only studio anymore and has to change, such lots before them (Bioware, EA, Obsidian soon I guess now they are ruled by microsoft). They all sold their souls to "many more easy" money.
The only try of upgrading oldschool RP>G gameplay is Dragon Age and it was 6 years ago for DA:I. Hey DA:I had the same base gameplay as BG (RTwP) and it has been a real success. I'm not considering Larian should have done the same. DA:I is not such a great game to me but RTwP could also make money... It just need a little bit more risks and ambition.