I know that. It’s not entirely true that it’s open-source, since it does not actually have an open-source license, but it’s true to an extent that the source code is technically out there and anyone who doesn’t work for CDPR can (illegally) use it. The comment was only meant as a joke, I wasn’t trying to be real serious about it.
It just looks like “Loo wan tee” to me.
Edit: Actually, just read the article, and considering the name Luanti is a mix between the Finnish word “creation” and the LUA programming language; and I’m preeetty sure LUA is pronounced “loo-wah” or “lew-ah”, I think the Luanti pronunciation is more likely to be “loo-wun-tee”.