I'm not so sure he would bring Lawyer back. One of the problems BB had with Lawyer was attitude, on the field and in the locker room. He was something of a clubhouse lawyer, part of the old culture of entitlement BB had to really work to overcome. Much like Ty, Lawyer was one of the veteran leaders who sipped the koolaid but never really liked it much. But he went along to win - once. He's one of the reasons Richard has such strong convictions about individual respect = $$$.
In Patriot Reign Holley told of the post 2002 season coaches meeting where players are evaluated. When Lawyer's name came up everyone automatically gave him the thumbs up saying while his numbers were down he was still a playmaker. BB challenged them to show him on film one big play Lawyer had made that season. Remarkably they could not, because it was all perception based on the assumption he was a key player. One ring was enough for Lawyer and he lost his drive as much as his skill. He has sdmitted as much from time to time since.
His dropoff coupled with the reality that he was not in fact a good team leader is the reason he is gone. Remember, he and Rodney were redundant, and one was going to have to adjust his game if both played. I think with an appropriate pay cut BB would have kept him for another season to see if Rodney's presence pushed him, but by the end of camp he knew he didn't have to keep him because his replacement was working out to be everything BB had hoped and a bit more, and Lawyer wouldn't budge on the $$$.
I think BB will always be a little sad he couldn't develop a real fondness for koolaid in guys like Lawyer and Ty (and even TJ and Drew). But he couldn't. And because of their former stature I don't think you ever bring those guys back. Down the road in diminished roles, those old resentments can create a killer undercurrent in the clubhouse. Ty had more potential going forward because diminished skills aside the older he's gotten the more self motivated he's become to prove himself regardless of rings or injuries. And leadership was never part of the Ty Law package anyway.
FWIW his close friend Borges says contrary to any public sentiments he expresses from time to time, Ty harbors serious resentment and will never come back here under any circumstances that include BB. I imagine the same could be said for Lawyer. While these guys maintain close off the field ties to their friends on the current team, the workplace dynamic having them back in the locker room would create for those friends (most of whom are now team leaders who have accepted home town discounts and renegotiations or will yet be expected to) would negate any on field contribution they might still be able to make.