"Totally rigorous and reliable", it says. Is that a balanced assessment? The "totally" part of that is, surely, over the top. In fact, it is doubtful that can ever be attained by a chess historian, except perhaps one with very low output and, happily, Whyld was not in that category.
I know from my own Staunton studies that he contributed a great deal on that subject for which we should all be grateful. In the related field of Morphy and Edge, his reputation stands far from unblemished. He misled the chess world over the "lover" letter. For those curious about the details, easily the best coverage of the Edge, Morphy and Staunton controversy is to be found in Edward Winter's "quartet" of feature articles which were mentioned in C.N. 11854 -
https://www.chesshistory.com These articles include much debate between historians on the controversy, from which Whyld emerges severely battered.
"At his best, he was one of the best; at his worst, he was one of the worst", was how Winter once described Whyld.
https://www.chesshistory.com/winter/extra/edge.html
The Oxford Companion to Chess is a marvellous achievement which must have been of inestimable value in popularizing chess history among players.