In Cybernetics, he does credit Maxwell, Pitts, etc. He goes through the entire history of science relevant to Cybernetics for the first and second chapters.

He did invent plenty of feedback analysis techniques and modern control systems before writing Cybernetics

There are many developments relevant for cybernetics that were not mentioned in the book Cybernetics, like discoveries of H.S. Black and other engineers in Bell labs, or early mechanical analog computers. Here is a short review of book on the history of control engineering before cybernetics: https://onlinelibrary.wiley.com/doi/pdf/10.1002/acs.839

"[...] general reader could be forgiven for assuming that Wiener was the originator of the idea of feedback control. Significant though these war-time contributions were, they were not the whole story: as I and others have shown feedback control has had a much longer history"

That text includes more references to papers and books on the history of ideas relevant for control theory and control engineering.