There was a good reason to allow name changes. With this new enforcement Southwest is practically begging group leaders to book refundable tickets for the new passengers, use those tickets to pass TSA, then cancel those tickets (or not) and have the new passengers board using the paper boarding passes of the absentees. Such a reaction by group leaders could cost Southwest revenue by preventing sale of additional full-fare tickets.
Nope. Unlike regular Southwest tickets, group tickets are not cancelable. Once purchased you can change names, but that's it. And now, starting 72 hours prior to the flight, you cannot change names. As a result, if someone gets sick, their ticket is a total loss.
Now the only advantages of group tickets with Southwest are 1. a minimal discount (generally 5%, though they sometimes cost MORE than regular tickets because some sale fares are not included), and 2. the convenience of having a single record number. These are absolutely not worth the risk of having to, essentially, throw away the ticket if someone cannot go at the last minute.
There are other factors that make Southwest group tickets a PITA. Though one can check in online, one cannot print boarding passes. This means the group has to show up at the check in line and get agents to print every BP at the airport. The kiosks do not work for group tickets. This causes frustration for both the agents and any other passengers stuck in line behind the group.
Additionally, they do not accept credit cards for group deposits (only for paying the balance due). I've found it to be a bit of a challenge to get our business office to do the LOA for an e-check. It makes them anxious. Of course this is still better than when they only took paper checks!
I am done with Southwest Groups. Too much risk for so little reward.