No, I think the articles state that the Kindle Fire make it very difficult to read material not purchased from them, regardless of format. I have read elsewhere that the KF treats side-loaded material like viruses.
Here's the link to that comment:
https://www.mobileread.com/forums/sho...2&postcount=11
We should be questioning if we want a company that adopts such an exclusive strategy to control a majority share of the digital book market. How can that be a good thing?