> Source available means you can see the source, but not modify it.
No, it doesn't mean that. To quote the page I linked, emphasis mine,
> Source-available software is software released through a source code distribution model that includes arrangements where the source can be viewed, and in some cases modified, but without necessarily meeting the criteria to be called open-source. The licenses associated with the offerings range from allowing code to be viewed for reference to allowing code to be modified and redistributed for both commercial and non-commercial purposes.
> This is kinda the opposite, you can modify the model, but you don't see all the details of its creation.
Per https://github.com/meta-llama/llama3/blob/main/LICENSE there's also a laundry list of ways you're not allowed to use it, including restrictions on commercial use. So not Open Source.