Exactly how many members of the gang are still alive and at large is not known. In Soul Music, Lias Bluestone, reflecting glumly on the diamond rings worn by Chrysoprase comments, "They say that when they found the DeBris gang, none of them had any teeth." This seems to suggest that the gang had already been killed by the Breccia, however they are seen alive and well running from the watch in Hogfather and referred to in Jingo also (they had broken into Vortin's warehouse, but this seems to be a hobby among all criminal groups in the city). It seems, then, that some of them are still active. Perhaps they had their teeth knocked out but were allowed to live.
The gang are referred to in stories only from the times when they are beaten up or arrested, which makes them sound like an unsuccessful organisation, but for all we know they could be carrying out profitable hauls all the time and only getting in trouble now and again.