How true and official are news from popular tech Twitter profiles like EVLeaks and MMXNewscaster?
Blogs say that @evleaks had leaked news about Nokia Normandy and MMX Newscaster had leaked news about KitKat for Micromax models
A source from which you get regular stream of rumors which later on turns out to be true can be said to have a second thoughts on their rumors,leaks.They build their reputation on how true their leaks turns out to be.
But never consider leaks to be official as they are not always true.
I wouldn't put these two in the same category, as one (@evleaks) is a well-known source for leaked news and rumors about forthcoming phones and has 122k followers. The other has 3k followers and looks to be tied to a blog which hasn't been updated in months.
In terms of @evleaks, the guy behind it gets a lot of things right, and clearly has inside sources. However, he isn't always accurate. So it has some worth but only as much as a regular rumors-centric website. You're better off taking everything with a pinch of salt and waiting for official announcements.