From PR discussion on GH:

I made ID_LIKE a special case because it's likely a users will use the field in a wrong way. The issue won't be detected in common CI because the field is either not present or contains a single item for majority of Linux distros. Common values are debian or fedora. For example Ubuntu has ID_LIKE=debian. Only very few distros have an ID_LIKE with multiple entries.

Victor asked me to remove the special case because splitting is trivial. In that case users would have to split the field and always check for "name in info["ID_LIKE"].split()".

The special case makes it less likely that users get the field wrong and reduces their burden.