COM: Solarian summoning zeniths clarification

[Minimight]

In the COM, Solarians got access to two new Zenith Revelations, one photon and one graviton, which both do essentially the same thing: act as a summon creature spell. However, there's one line in them that is leaving me puzzled:

COM wrote:

You select which four creatures you can summon each time you gain a solarian level, and they must all be shadow creatures.

For photon, just swap "shadow creatures" for "fire creatures".

So the first part, "You select which four creatures you can summon each time you gain a solarian level," seems pretty clear to me. Summon Creature works by letting you choose four creatures off a list based on the spell level. So you can change which four those four you choose every time you level up.

The second part makes no sense. "...they must all be shadow creatures."

Shadow creatures are one, specific creature that you can summon from the Summon Creature Table. However, that could also be implying that the creatures use the shadow creature template This leads me to two interpretations.

1. You don't actually get to choose which four creatures you summon, and you only summon shadow creatures (though you can of course flavor them to be any shape you want).

2. You do get to choose which four creatures you summon, and you apply both the creature's original template and the shadow creature's template.

[Xenocrat]

It’s 1). For it be two they’d have to say you take the fiery or Umbral grafts on top of an allowed alien (of which there are very few and still couldn’t get you to four per spell level).

[HammerJack]

I figured it was a bit of future proofing, trying to leave the door open in case your game has been expanding the list of allowed summon creatures, to keep up with releases after the 1st Alien Archive, since that could, over time, leave you with a large enough set of creatures that can be described as "fire creatures" or "shadow creatures".