I still haven’t heard a convincing argument to not use .local and I see no reason to stop.
Mainly conflicts with mDNS. However it’s shitty IMHO that the mDNS spec snarfed a domain already in widespread use, should have used .mDNS or similar.
I’ve also used .local but .local could imply a local neighborhood. The word itself is based on “location”. Maybe a campus could be .local but the smaller networks would be .internal
Or, maybe they want to not confuse it with link-local or unique local addresses. Though, maybe all .internal networks should be using local (private) addresses?