Pashute Yid,
I highly doubt that artscroll story. They are smart enough not to copy from another source without attribution and permission. That would make them look foolish and possible open themselves up to a copyright infringement lawsuit.
I haven’t looked inside an artscroll gemara to see if they do attribute to steinsalz because I don’t own an artscroll gemara, but I highly doubt they would have legitimized him by doing that.
By the way do you own a large fleet of cars? I’ve been seeing a lot of bumper stickers lately with the phrase “I’m a pashuter yid” 😉