PUC's Lua is, however, open source (https://www.lua.org/license.html), even if they don't solicit contributions, and they do accept happily accept financial support. It doesn't look like they release new versions very frequently at all (the last release was in over a year ago). Still, it appears they do accept financial contributions, so it seems like Roblox, whose market cap is $22 billion and whose offerings are at present entirely dependent on Lua, should probably consider offering at least token support (https://www.lua.org/thanks.html).
Why does the market cap allow you to decide about other people's projects? Lua is used in many places, and its users aren't all employees of Roblox. Lua is popular because it works in a way that sometimes breaks backward compatibility, making the language as easy and lean as it is. If there's a disagreement on how it should be used, just fork it like Roblox did.