Cheap insurance to change the pulleys at the same time. Same for the water pump. Your in there, so do it.
Unless you live in extreme weather area, 70k miles it bit too early for replacing timing belt. Did they show you the oil leak? if yes, then it may be ok to go ahead and take care of both oil leak and TB change together. If oil drips on the belt that could weaken the timing belt. When I had timing belt replaced on my other car, the old timing belt showed no signs of wear even after 90k miles(7years).During a recent visit for software update for my 2016 MDX Advance, the dealer suggested timing belt change. At 70K miles, it seems a bit early, but I was told that the suggestion was based on 7 years. It was noted that the belt tensioner has a bit leak. Shall I wait a bit longer or do it now? thanks.