Speaking of that video, I don't think I can support Samsung Pay.
MST makes for a better customer experience in the short term. However, it also keeps a technology alive that should arguably have died a decade ago. Already, most places aren't bothering to enable NFC along with EMV. They might later on, but some might also get swayed by the promise of "we don't have to do anything to support Samsung Pay" and just never bother enabling NFC. In the worst case, Samsung Pay could even significantly delay the adoption of EMV by reducing fraud losses from merchants who didn't bother to upgrade their terminals.
I don't know how likely either of those possibilities are, but I'd rather people focused on getting NFC working than keeping a crutch alive indefinitely.