That's because they don't make different versions. In fact, renters often enter a profit-sharing contract with the distributor (a few major distributors cover 90%+ of films) so they don't have to buy stock up front, or just buy a license from a wholesale distributor (representing several distributors) that has sub-license rights. It's often the wholesalers themselves who manufacture the DVDs.
Yet they all have the same warning.
Standard industry boilerplate, often put there by the wholesalers.
And in the case of Baltimore, the films were cut for exhibition there (John Waters had to deal with the censorship board cutting his films before their hometown premiere).
As I said, it depends on how it was done. There's no question of copyright infringement if they made Waters cut his own films before they could be shown. There is one if they cut his film and then showed it. That depends, of course, on whether they had a license from Waters or his estate (or whoever the current copyright holder or license manager is) for a public exhibition of his films.
Viacom's Blockbuster maybe. None of the Mom and Pop shops have the finances to participate in this.