Let's be clear: this Tingley/Huybers paper is a proof-of-principle of an entirely new method of reconstructing past climate. It is not intended to be a "confirmation" of the MBH hockey stick, which Martin Tingley was very clear to tell me, though the preliminary results obtained so far have many similar features. Nor is it intended to solve every problem in the field of paleoclimatology, let alone purported problems in the data. (From my reporting, I think scientists believe that that data is pretty good, though data in any scientific field can _always_ be improved, and _is_ always being improved). In any case, this new result ought to, I think, damp criticism that the PCA approach was somehow unsound or flawed, as some have implied.
By the way, I asked Wegman for his thoughts on this new method, but he did not respond.