The big problem in this field is actually proving you have a majorana fermion. In this experiment they measured a zero bias conductance peak, but this can de caused by multiple other things as well. There are other detection methods as well, but the ultimate prove is using two majorana's and "braid" them together, thus forming a qubit. Doing this is much harder, but is also the primary use case for majorana's, so it is necessary anyway. Until someone does this with this system I would take this measurement as a strong indicator, but not a real breakthrough.