It's a good thing this was done. It would certainly make things a lot easier in court.
That's one important thing when it comes to "search warrants".
One charge cannot be made unless it is related to another charge.
If the police had a warrant to search your house for stolen 32" televisions and they found a bag of weed in your kitchen drawer, they can't add charges for possession of marijuana because it was in a place that you would NOT find a television. Therefore, the search was "unreasonable".
At first, they FLDS issue started with abuse. Charges of incest, statutory rape, etc couldn't be immediately brought to attention since it's not directly related to abuse. Now, everything is there in the DNA tests. It cannot be overlooked. So, if they do find evidence that some women were minors when they became pregnant, then charges of statutory rape could be brought forward... and evidence that they came from incest, then those charges can be brought forward as well.