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This may be more than one issue. We will need to answer for the DoC.
I don't even have https://lists.w3.org/Archives/Public/www-style/2011Dec/0481.html in my mailbox, which is odd. Nobody ever replied to it, which makes me wonder if it even got through to list subscribers.
I believe reversing is now defined, per resolution of the working group, and the spec is also more precise. More recently the automatic reversing has been integrated into a precise definition of transition starting and cancelling. Hard to respond to the email, though.