The lack of ToP characters makes sense. The DLC list was most likely partially finalized before ToP came out, and the only reason 17 made the cut was they already have existing assets for him, not need for a brand new character like you would need for Jiren and Kefla.
Also money reasons. Release a ToP focused sequel, expansion pack, or season 2. Print money.
Also money reasons. Release a ToP focused sequel, expansion pack, or season 2. Print money.