You’re correct bout the black sport band gen3. That one came with the Apple Watch Series 4 and 5 SBSS. all included Apple Watch bands do come in a retail box with series 4 and later watches to also allow you to choose whichever strap you want at an Apple Store or on the Apple website, but the boxes don’t have a barcode if packaged with an Apple Watch. My deep navy one that came with my S6 gold stainless steel has no barcodes on the box.
A friend of mine has the same Apple Watch Series 7 Edition as you. He did get a Nike band originally with it (it broke after a few years) and told me he did have a light grey sport band in the box, just that he lost it but it looked like the one on bandbreite.