Hourman II played a part in getting Grundy freed, which led to a big brawl between the villain and Pat in the S.T.R.I.P.E. suit, which then led to Hourman II nearly taking Grundy’s head off.
Not that it would be easy for Solomon Grundy to live a casual life in Blue Valley without attracting tons of attention.
However, that worst case scenario (for Grundy) didn’t happen, allowing for his return in the future.