Archmage & Shadow Adept

[Tamamo]

While I was looking through the list of custom PRCs, I noted that Shadow Adept is not on the list for Archmage's cross-classing options despite being a pure caster like the rest of the listed PRCs. Considering that the post for Shadow Adept was made around five months after Archmage, was this an oversight or is it deliberate?

[Valefort]

Oversight.