For as long as English has been discussing phobias and philias, the convention is that one takes a Greek root and adds the Anglicized -phile or -phobe for a person, or -philia or -phobia for the abstract. Typically the spelling conventions are Western, so acrophobia rather than akrophobia.

There are only a few recognized exceptions, such as aquaphobia, and that's because hydrophobia is an antiquated term for the disease rabies. Neologisms clearly don't follow that, such as transphobia or Islamophobia (though the latter technically is identical to the word in modern Greek; it just doesn't appear to have been used prior to the Early Modern period in Greek).

In this case, there is an existing word, eclipsophilia or ecleipsophilia (depending on spelling). For shadow it would be sciophilia, for darkness it would be scotophilia.

The point is not just that someone coined a term; it is that the person coined a term attempting to be clever but failing to note an existing term already existed and failing to take into consideration that there is already an established convention in the naming of these things.