As someone who hasn't watched The Mandalorian or TBOBF, I say post it, especially if it's not Mando/TBOBF fic or the audience doesn't need to have seen Mando/TBOBF. There is always a dearth of original worldbuilding in fandom! And yes, you can always state that these Tuskens are from near Mos Ila or something, unlike the Anchorhead/Mos Espa Tuskens of the other media.