I was taught to do it the other way round - that the last thing you do is take the frictions off. But I just checked, and you're right about the check list. No-one's ever mentioned it before, but what you say makes sense.
On a slightly related point, I hope all instructors tell their students to put the check list away before releasing the frictions. Some R22s will take off by themselves without the friction on, if you take your hand off the collective! I'd had that happen, because no-one had told me.