You are triple-posting..on a thread that has been dead for two nearly two and a half year's.
With the success of Springfield for both Orlando and Hollywood, and with the removal of the attraction for a nicely themed Despicable Me land; I don't see Back To The Future returning.
Does that mean Springfield and the upcoming Despicable Me land at Osaka is safe? There are a lot variables to factor, but with both being insanely popular IP's that there is a crowd for; I don't see it leaving anytime soon. Especially with the major investments put into it throughout the past few years, both at USH and UOR in-terms of Simpsons.
And as for Despicable Me, it is one of their shining jewel's of IP's right now, and it's in-house. Not even wondering about how much it makes, I think it will be safe for the time being; unless if the film severely tanks that is coming out this year.