I thought B-4 was salvaged as part of the resurrection of Data. I didn't recall his part in the Breen 'incident' but I looked it up on Memory Beta and yes, B-4 was captured by the Breen and rescued. Soong removed Data's memories from B-4 because it was causing problems for B-4 and that's how Soong resurrected Data into himself. B-4 then returned to the Daystrom Institute by his own choice to help Dr Maddox (who was the one that rallied to B-4's right to self determination). Lal is also revived though, yes. She is with Data, though she, like most girls her age has a mind of her own. But Data managed to do that with the help of Flint (now known as Vaslovik--forgive me if I spelled that wrong) who had revived Data's mother already.