Hooke was fond of publishing his ideas as ciphers. Ideas in his time were often discovered simultaneously in many places at once, and so I think the purpose was

Hooke was fond of publishing his ideas as ciphers. Ideas in his time were often discovered simultaneously in many places at once, and so I think the purpose was not to convey the solution, but to provide a sort of proof-of-work that he had found a solution without letting anyone else take credit for it. I guess he expected the answer to be discovered somewhere else fairly soon thereafter, maybe by one of his colleagues, at which point he could unscramble the anagram and say "see, I beat you to it".