This depends entirely on your definition of "moderate to large". Many real world problems can be solved easily using existing MILP solvers. We will likely never find an algorithm that can solve arbitrarily large instances of NP-complete problems in practice. Heck, it's easy to generate lists that are to large to be sorted with O(n^2) bubblesort.
It is sometimes possible to specialize algorithms and implementations to be faster for certain subdomains of the overall problem, allowing real-world-useful problems to be solved in reasonable time despite the generalized theoretical complexity bound.
If this new algorithm is a fundamentally different approach from the current ones, this may allow ILP to be used in domains where it is currently infeasible. Vice versa, this new algorithm may not be feasible in domains where current tools thrive.