But then Daawat may actually means something else, as the primary meaning of the word is 'invitation'. And while I don't know yet if the producer-director of the movie are interested in which meaning, to me 'invitation of love' would make slightly more sense than 'feast of love'.
As far as Urdu titles and meaning is concerned, Habib Faisal last made Ishaqzaade, whose meaning wasn't too correct despite conveying the idea of what it is about.
[PS: If you doubt that the word can be used for invitations without a party or not, try a mushaira, where poets give each other a 'daawat' to come on the stage. I can tell you there is no food involved there.]