I you are happy with the price, I would probably book the flights, with a couple of caveats:
1.) Your flight times WILL change. Know this going in, and it can help with a lot of stress. If you're flying into FLL for a cruise, I'd probably book to go down the day before the ship sails, so if there are drastic time changes, you're not scrambling to make the ship.
2.) If the flights are non-stop, they may be changed to one with a layover or connection. While this might still be a concern in Syracuse in March with weather issues, I'd probably roll the dice, and book them anyway. Years ago, back in the dark ages, when we all still used travel agents, I had a great one. The one thing she told me about connecting flights, that if you're travelling in the Winter, and have to connect, do it as far south as you can, as you run less risk of major delays.
3.) I think Delta will still be around and will still be flying. Just not sure what's going to happen with their flights to leisure destinations. (i.e. changing from non-stops to layovers, etc).
All that being said, if I could live with the price, and book a day before a cruise, I'd probably go for it.
Good Luck!