I might be missing something here ? but the single "My Generation" was released in 1965 and the film "Quadrophenia" was released in 1979, the single was re-released a few times after that, but it was most definatly released well prior to the film coming out.
The film is SET in 1964, a year before My Generation came out.
When he puts My Generation on the record player at the party, there is an album sleeve in the background of a double album - A Quick One/The Who Sell Out - which were released in 1966 & 1967, with the double being put out years after that