Fr tho ?

They probably paid more to the workers at Roblox to make a new sound instead of just keeping the "oof" sound :(

yeah..
Even though it was like 20 dollars roblox is a mega corp

It wasn't exactly $10, but the actual fee was still probably equivalent to a single penny for them. And they decided to sell out instead.

A couple of games managed to bypass it and still have the OG death noise, but it's still ridiculous.

So they decided to to keep it, but be lazy about it and make a new death sound instead?

Not exactly. I think what actually happened is that some popular old school creators have had more than enough money to buy the rights to the originally sound, and some of them did in fact decide to get it. But I can't say for certain that it's correct.

Some of their videos have uncopyrighted sounds in the first place.