This appears to be a reliable source though, and this does seem to be one of those cases where information about the shooting of a movie has leaked before the studio has had the chance to officially announce it.
In fact, Badass Digest claim to have heard from a reliable source that TRON: Legacy 2/TRON 3 is happening, and director Joseph Kosinski will be back to direct! The aforementioned blog also say that Garrett Hedlund will return, but that feels more like speculation on their part rather than completely concrete information.
To make this happen, you have to imagine that some budgetary changes will have to have been made, but the fact that it’s going ahead at all will come as welcome news to fans of the classic original 1982 movie.
When HeyUGuys caught up with Kosinski almost exactly two years ago to the day, he offered an update on TRON 3 and promised that they were working on the script and have a very “exciting” idea for it. See that video below from 4:00 onwards.