Hi, I think what the first person said should not be the language, but that different regional versions cannot be installed at the same time. I mean these codes are in one environment.
For example, below is the download link of BC22.1, you can see W1, AU, CA and other versions, these cannot be installed at the same instance.
https://www.microsoft.com/en-us/download/details.aspx?id=105218

As for languages, multiple languages can now be installed in one build.
You can find the language pack app files provided by Microsoft first party in the folder below.
~Dynamics.365.BC.56216.W1.DVD 22.1\Applications\BaseApp\Source

Hope this helps.
Thanks.
ZHU