If the catalog said that the fitting was equivalent to AN-XYZ or conformed to some other spec, I say yes maybe you had some guarantee of conformity to some technical requirement, I don't see that in the Spruce Catalog. I just see a Spruce P/N.
Does Spruce have PMA approval to manufacture parts that are replacement parts for aircraft? There is a category of PMA parts approval based on open specifications, but I don't see how with this situalion would apply.
In the part 121 world, as soon as you sell it under a proprietary P/N the only way to represent it as a replacement for an an airframe OEM part is for the part manufacturer to have PMA for the part.
I don't know how it works with GA, but how does anyone trace the Spruce P/N to the raw materials and manufacturing craftmanship required to make an aircraft part? I would have expected the FAA MIDO would have to approve it.