Doesn't the article go over that?
Where? I only see in "conclusions" that StrictYAML is recommended, but this is only about the implementation not the format itself.
TOML is mentioned but I do not see wide adoption, e.g. no up-to-date Java or similar implementation. (https://github.com/toml-lang/toml/wiki#implementations)
Additionally I think TOML is more verbose compared to YAML but avoids the indentation ugliness.
If you're in the Java world, HOCON is pretty neat.