It depends on what is a Theory of Change, and how it has been generated/shared.
If it remains the same as a big logframe, hidden in some proposals... it does not add much value.
If it is co-generated and owned... possibly EMERGING from the process of change, then it is an added value.
As an evaluator, I see that staff on the ground welcome discussions at theory of change level when they help to systematize experience.
But they might be clueless and confused by TOCs as proposal annexes.
So, if the Theory of Change is just bureaucracy it is actually a complication.
If it is a process of systematizing experience, owned by these involved in making change, it is super useful.
Unfortunately, the latter are very rare.