Co-author here.

This is not the same method at all and this is much more reliable. For King Tut, they used ground penetration radar, which is very hard to interpret. Here: (1) this is confirmed by 3 independent teams using 3 different detection technologies, (2) we used the same statistical criteria as for discoveries in particle physics (deviation 5 sigma from the model).

In addition, we clearly see the new void on Nagoya's data (Fig.2).

Unfortunately, cosmic-ray muons cannot be used in King Tut tomb because we can only see "above us" (the muons come from the sky).