I choose to be supportive rather than pessimistic by default. Sometimes that faith is part of the alchemy that helps make magic happen. I believe Telltale realise this is not just another project for them. It is a milestone and a possible point of departure for significant expansion.
They are bound to know the handling of this property will have a significant impact on their future, moreso than the finite Back to the Future and Jurassic Park franchises. So I think past projects alone are not necessarily an entirely sufficient guide to what we can expect here.