Hi,
Thank you for your suggestion!
There is an aria-hidden=”true” as well as the styling is explicitly set to “display:none”, so this is not going to conflict with accessibility readers – these two attributes strongly suggest, that this is a non-input (which is correct). WCAG tools may trigger a warning message (some does not recognize the aria-hidden and the invisible styling), but because of the invisibility, this is not an input.
Wrapping around a fieldset with a legend is probably not a good idea, as an actual reader may think, that there is useful input there, while this is a hidden field, and should be ignored.