bitbucket.org and blog.bitbucket.org are different applications running on different servers.
We recently migrated our WordPress instance to a new machine, but not all of the configuration was moved over. We've put caching back in place, so it should be back to normal.
I think "can't read" would also include the case of "haven't read". Making the "haven't read" component somewhat redundant.
Aesthetically it doesn't scan well - I think adding it in parens would be the way to go if you want to make that kind of emphasis.
Haven't read (and can't) ...
If the question is about whether it is grammatically correct then I wouldn't like to say - I never really paid much attention to those rules. :)
Disclaimer: haven't read and can't read the article. EDIT cache is here: http://webcache.googleusercontent.com/search?q=cache:http://...
(Totally OT: would it be correct to say "haven't and can't read"?)