I don’t seem to recall news of a third Lost Boys film being made.  I still have yet to see Lost Boys: The Tribe.  Although, from what I understand on that 2008 direct-to-DVD film, I can take my time.  A lot of time.  As much time as I need to.  Regardless, there is a third film out: Lost Boys: The Thirst, and the trailer is now up at YouTube (I caught it at Collider).

The synopsis (via Wikipedia): When veteran vampire hunter Edgar Frog finds himself destitute and
almost friendless, he thinks he has hit rock bottom, but then
vampire-romance novelist Gwen offers him a small fortune to go on a
vampire hunt and rescue her son from an alpha vampire. With the help of
his friends, he prepares for a bloody battle.