Has it though? What some people thought was the "official story" at any given time might just have been a mishmash of various media reports and speculation (not just mainstream but also Alex Jones and the like), Reddit detectives, Twitter feeds, etc.
The criminal complaint filed against Dzhokhar is probably the best source as to what the "officials" are saying that they believe the "story" to be.
Or that he's been conveniently silenced by a throat wound