Actually, Project Reality hasn't been updated recently on their end. Yes, their code is still public and being used by other servers and being added onto by server owners, but the project its-self is basically abandoned. Their last development update(based on forums) is in 2014, http://www.realitymod.com/forum/f586-pr ... discussion
TacBF isn't moving to PR, but Frontline(another arma mod that's currently in development, and known by TacBF members cause of previous owners/devs) is infact using Project Reality framework. Right now, its a simplified, vanilla based A&D game-mode. Again, currently in development and not yet finished.
That being said, it doesn't mean TacBF is closing its servers, nor are the devs stopping development on the mod. Both Frontline and TacBF are run by different admin teams, different developers, etc. While you still see some around on forums, their focus is their own game-mode and that's what they're actively doing at this time.
This might slow down development/bug fixes on TacBF, as we've lost some of the dedicated staff we used to have, but it won't stop it. Eyeball is working consistently to keep new content, new features, new game-modes, etc.. coming to the TacBF servers and I hardly doubt he'll let this get in his way of doing what he's been doing for the past few years. Anyone looking to help him, I guarantee he's always looking for new people to help assist in bringing new things to the table.
tl;dr: TacBF is not moving to Project Reality. TacBF will continue to be updated. Eventually, we'll be back to having full servers when things work themselves out. Only thing we can do is continue to show our support to the developers and wait for things to get back to normal.