Wolf, it was a response to the Chachem Einer.
The eighth day was established because of a Safek but it in itself is simply Miderabanan. Gebroktz is more a Chumra than a Safek. You don’t have a Tzad Issur; you are merely Machmir in case of something.
Anyone who at this point will call an Hanhaga of Gedolei Olam a Minhag Shtus has bigger problems, as well.