This report indicates the BH area law based upon General Relativity (GR) is supported by the gravity waves studied so a good test here. The BH shrinking and disappearing over time is dependent upon quantum gravity. Quantum gravity is not confirmed in this study. As space.com reported, "According to the researchers, their results are pretty much in line with what they expected to find. The theory of general relativity — where the area law came from — does a very effective job of describing black holes and other large scale objects. The real mystery however, begins when we try to integrate general relativity — the rules of big objects — with quantum mechanics — those of the very small. Weird events start to take place, wreaking havoc on all of our hard and fast rules, and breaking the area law completely. This is because black holes cannot shrink according to general relativity, but they can according to quantum mechanics."
Other conflicts exist too between GR and QM like the cosmological constant and rate of 3D space expansion.