I'll admit I read deeper into your argument than what you actually wrote.

Comparing with a platform like a digital distribution storefront, the infra & support & other OpEx still has to be paid. Could be argued that the developer has more choice on what to spend it on in the case they are given revenue directly, and in that case it would be their OpEx. That's why I think it's equally reasonable to consider it either as developer operations cost or a business one.

Other platforms routinely state that this money is given to the developers directly, which I suppose is true (given they also often host offline singleplayer games with generally much lower ongoing costs than multiplayer, which Roblox doesn't). Their communities also routinely refer to the money interchangeably as a "profit"/"revenue" cut, which I think is less forgivable and probably an indication of larger terminological clarity problems in the game industry regarding these cuts than just Roblox.