Quick review: I like the vendors take on using a reverse squeeze page. Yes it will get less opt ins but is geared toward getting more sales and a stronger bond with your subs from the start. I'm not sure if personalizing the oto page with the email address will make a difference, I think what you offer and the price point are the biggies here.
I do think the scarcity element is good. Not groundbreaking this part but I do not see that many marketers doing this with their oto's from front end squeeze pages. I know it will be hard for most to get around not getting as many subs.
My take is that it is worth testing. If you already have a squeeze page funnel working for you then test this with some of your traffic and get stats for all sales in the initial follow up sequence. Then decide which approach will work best for you and go with it.
Overall nice to see somethings that are not covered in most of the rehashed wso's that cover the same basic newbie stuff while promising a gazillion dollars!