Arpan Banerjee and Adriaan Dekker spotted a new Google Shopping feature called “hidden products”.
As shown in the screenshot, one of the approved products is hidden. The meaning behind “hidden” remains unclear. These products appear to be approved but may not be eligible to serve in ads or listings for unknown reasons.

It may be related to product visibility, which the Google Ads Help Center describes as an indicator of whether your product appears in ads or free listings on Google. The status normally shows as either “Visible” or “Not visible,” but in your screenshot the value is shown as “Hidden,” which is different from what is documented.