If they add a tier 4 to weapons at some point, I can see some form of sword (doesn't have to be a katana) as the next tier after a machete. But that's about it. As Uncle Al said, they try to keep each class of weapons distinct from one another. Adding another weapon that's basically the same as the knife class is really nothing more than cosmetic. Now, if they added cosmetics for weapons so you can just change the look, then that would work.
So yes... I'd like swords, but I don't expect them unless there is a tier 4 for weapons or they allow cosmetics. Or perhaps as part of their legendary weapons plans, if that ever happens.