An older answer to that question can be found here
There was also a link to be found to a blog with some pictures of B-29s which did launch the nuclear bomb in August 1945.
Hi, while more can be said, you seem to have linked to the answer yourself. This older thread by /u/restricteddata (the author of the blog post you linked to) also answers this -- use of atomic weapons in Europe wasn't contemplated due both to timing and lack of heavy bombers to drop them (the B-29 was not deployed to Europe).