This is a strange argument given that the new prophets have multiple features that deviate from the original. Is aftertouch and USB midi a bell or whistle. Haha.
Aftertouch, USB, MIDI, velocity, Fatar key system instead av J-wire, flash firmware and possibility to program every parameter from a modern DAW (tried out to program multistage envelopes, LFOs etc - awesome) has nothing to do with the classic sound but are modern and great features added.
Any portamento mode, if used as monosynth or multitracked, can be achieved via CV/Gate.
I think Dave Smith and his Sequential team has made an outstanding rev 4 of the classic Prophet 5. The only thing Dave missed is the classic batch at the rear, but I can take that