Not childless, but dependent-less... Colby doesn't seem to have been an issue for them. Chad's kids are all still alive too. All the one's who were dependent upon LV for support (financial, food, housing) are now deceased, but older offspring who are on their own and no longer dependent on LVD or CD don't seem like they were headed to the chopping block. And all the other players who had children (under 18) seemed to have abandoned their marriages and dependent children to remarry/date others that seem to have done the same (MBP/IP, MG/DW, and most obviously, CD/LVD). Alex/Zulema seem to be the only exceptions, but Alex didn't have any kids and all of ZPs kids seem to be over 18 and they were both already single, so that part doesn't apply, BUT if AC was the hitman and was found to have a big mouth ( re: conversations with MG), then he would obviously need to go, but the only way for a life insurance policy to be paid to anyone that could benefit the cult would be to get him married off. Otherwise, my assumption is that his parents would be his next of kin seeing as he was unmarried and childless and would therefore receive any life insurance payout. Or in the 2 weeks that he and ZP were married, they could have both taken out life insurance policies and named each other as beneficiaries. And I doubt AC would have thought he was on the chopping block, but ZP could have known he was and that's why she married him. Remember, according to the people at the Vegas chapel said it seemed like a very business like transaction.
This is all my own speculation, but it works with all the known info.