I'd heard that both Armstrong and Aldrin ditched their backpacks and boots, and that it was part of the plan.
It was definitely planned.
About the only departure from plans was the EVA, the plan called for Armstrong and Aldrin to sleep after landing and doing the EVA afterwards. Of course they didn't want to sleep and requested the EVA be moved up. Why anyone ever thought they would be able to sleep right after landing is another question.