When I covered that story back in September 2012 I predicted that Amazon would extend the requirement of exclusivity to the not-yet-launched Kindle Stores in Japan and Brazil, and it looks like I was correct.
Yesterday a reader looking at the pricing and contract info for KDP when he noticed something new. (Thanks, Robert!) I can't see that this has been reported yet, but apparently Amazon has indeed started offering to pay authors and publishers more money for KDP ebooks sold in Japan and Brazil:
70% Royalty in Brazil, Japan, and India: Digital Books enrolled in KDP
Select will be eligible to earn 70% royalty for sales to customers in
Brazil, Japan, and India. The List Price you set for Brazil, Japan, and
India must also meet the 70% List Price requirements for sales to
customers in Brazil, Japan, and India. If your Digital Book is not
enrolled in KDP Select or you do not meet the 70% List Price
requirements, you will earn 35% royalty.
I think we now have an explanation as to why the 70% royalty option was limited to a handful of ebook markets (US, Canada, and Europe); Amazon was holding out for a way to insert this exclusivity requirement. They've always wanted to be the only ebookstore, and this now appear to be the carrot they will use to get it.
It seems to me that Amazon feels pretty confident that they are dominating the global ebook market, but I'm sure that does not come as any surprise.