Do you need a Macbook Pro w touchID to test the authentication in your Swift app?
No, you do not need it to develop such applications. However you do need a Mac with Touch ID in order to completely test that feature. There’s no simulator in Xcode for macOS applications with Touch ID as such.

Usually it is not really necessary to actually test Touch ID though. It is a single line change to swap out Touch ID with local authentication so that you can test with passwords until you are satisfied that works, and then change it to Touch ID.

No one can know if you need this in the future. The future is, after all, still undecided.