They also haven't said it's coming to TGS, either.
I'm not saying it's wrong for you to try and put some quotes together and try to come to the correct conclusion, but if we've learned ANYTHING from SE over the years, it's to NOT get your hopes up. I sincerely hope you're right in FFXV being at TGS, but I think it's a bad idea to put all of your eggs into one basket like this and say things like you can guarantee it. What happens if it doesn't appear? How disappointed will you be? How disappointed will others be that you've tried to convince?
I hope it's there, but I think instead of being "100% sure" about it, simply be optimistic and prepare for the worse case scenario. That way, you won't feel as disappointed if you're wrong.
It's just best to try and ignore everything until the time comes, unless you get direct quotes from SE saying clear-cut things like "FFXV will be at TGS 2014." Until then, be cautious and wait.
That's my advice, anyway. Feel free to be 100% sure it'll appear and bet your avatar away if you like, lol.