I don't think it was delayed for the menu. Shu said the whole game was being redone from square one.
I don't remember that. They said it was back to the drawing board in a number of areas no?
If I'm reading right it sounds like the whole logic/code behind the social/online aspects just wasn't working out right. Clearly its way more than a menu and ties into matchmaking, searching for races, etc. Sounds like that's the area they had to go back to the drawing board on and re-design it and rebuild it again.
From other comments I suspect that performance issues with the dynamic lighting and having a 100% locked frame rate were also part of the issue although I seriously doubt they went back to square one there - I doubt they'd be launching 2014 if they re-started work on the core engine to that degree.
Anyway it's good to finally get some clarity and a release date again. I'm not too bothered by the 30/60 angle I'll judge the game on its merits and performance as released. The Plus version sounds like an ideal way to get a feel for it before deciding whether to plump for the whole game or not.