Ring of Cosmic Alignment
This majestic ring is forged from twin bands of mithral and adamantine. If you have the stellar mode class feature, whenever you start a turn of combat attuned to a stellar mode and choose to become unattuned, you can immediately gain 1 attunement point for the stellar mode that opposes the
mode you began your turn in. For instance, if you began the turn in photon mode and choose to become unattuned, you can use the ring to gain 1 graviton attunement point. Using this ability is a swift action.
When using Zenith Revelations you are not choosing to become unattuned, you are becoming unattuned by result. Which is not the same thing. If there was an ability that forced you to unattune that would not trigger the ring and in the case of Zenith Revelations, it does just that. So you can only get that benefit if you choose to be unattuned as a swift action which gets you a free point in the other attunement.
I concur with Steve's analysis.
Another way of thinking of it:
Is one choosing to become unattuned by using a zenith revelation? That makes the zenith benefit the (hopefully happy) side effect of the desired choice of becoming unattuned. In that case, the cosmic ring should grant the one point.
No. You can choose to become unattuned normally, and it has no benefits for doing so.
STELLAR MODE (SU) 1ST LEVEL
The stellar forces you call on are attuned to either photons (representing the power of stars to emit heat, light, and plasma) or gravitons (representing the power of stars to attract and imprison objects through gravity). The ultimate expression of photon power is the supernova, when all of a star’s energy is exerted outward, while the ultimate expression of graviton power is the black hole, where gravity is so strong that nothing, not even light, can escape it. The balance between these two opposing cosmic forces is the source of your power, and your stellar mode represents the strength of your connection with one or both of these forces—a relationship that shifts from one moment to the next as you use your stellar revelations.When in battle, you enter a state of metaphysical alignment with cosmic forces. At the start of your first turn in combat, if you are conscious, you must choose one of three stellar modes: graviton, photon, or unattuned (see below).
At the start of each subsequent turn of combat, you must choose to either stay in your current stellar mode or to become unattuned. If you choose to stay in your mode, you gain another attunement point for that mode. As long as you have 1 or 2 attunement points in a mode, you are attuned to that mode. Once you reach 3 attunement points in a mode, you become fully attuned to that mode. Some of your stellar revelations are zenith Revelations, which can be used only when you’re fully attuned to one mode or the other. When you are fully attuned, you cannot gain more points in your mode, but you stay fully attuned until combat ends, your stellar mode ends, or you become unattuned. If you choose to become unattuned, you lose all attunement points you’ve accrued so far. At the start of your next turn, you can enter a new stellar mode or stay unattuned.
So no, becoming unattuned doesn't equate to using your zenith mode.