Group Texting with Separate Reply Threads?

Has this feature been taken down? I used to be able to send group messages out to people not in my directory as separate text threads, now they are all grouped together. This is for gathering information for potential applicants and I don't want to be sharing peoples' phone numbers with others. As recent as a week ago it gave me a "warning" that it would be sent out as separate messages-which is the whole point for me anyway-then yesterday it is no longer is doing so.