I dont really want to do defend corpos but this move is anything but p2w roblox development. Like all game development companies provide further paid services for additional/expanded functionality. Then again, as roblox themselves said these costs are of no real interest for like 99.999999% of us. This is just stuff for super big games (which also generate quite a lot of revenue) to expand overall functionality.
Secondly, it would likely be in the interest of roblox to NOT reduce or restrict general functionality away behind a pay wall. Roblox is a corporation that strives off tons of games made by tons of people and trying to nickel and dime us while providing poor services will likely result in a quick death for the site. They would pretty much shoot themselves in both feet if they were to start pay walling development for all people. Them doing this would also likely be the perfect opportunity for competitors to come and knock them off their throne with simple claims such as “you can make games for 100% free!”
You could make an argument about how roblox now provides paywalled additional functionality which should have been free considering the current devex rates but eh. At least they are not removing free functionality and placing it behind a paywall. (Hopefully they arent doing that, lmao)