Hello, Mattermost is currently listed as being under AGPL/Apache, but it is seemingly more complicated than this: Some directories (server/templates, server/i18n, server/public, /webapp) are under ...
If you have some fos licensed software it will be foss forever, that licence is a contract and doesn’t go away. Now the author(s) of that code can license it to other people or release the newer versions with a different non-foss licence.
It isn’t really Open Source if it can become not Open Source.
If you have some fos licensed software it will be foss forever, that licence is a contract and doesn’t go away. Now the author(s) of that code can license it to other people or release the newer versions with a different non-foss licence.