Can guests somehow see my album before I've published it?

No. Draft albums are completely closed to guests — share links won't reveal anything, and there's nothing to find. This is a deliberate safety feature so you can upload a full event at your own pace, in the background, without a single guest stumbling onto a half-finished album. Only when you hit publish do the links start working. So the workflow most photographers use is: create as draft, upload everything, let the AI do its thing, spot-check, and only then publish and notify guests.