Regarding the "one-at-a-time" versus recall decision...
I don't know if they avoided recall for this reason, but you should (all) be happy that they did. Recalls take time. Lots of time. When a product run as large as early generation Rival shifters has an issue, a recall would cause people to be without their bikes for days, if not weeks. When Cervelo had their Wolf fork recall, we had to remove the fork, call it in, box it up, and send it to Cervelo. Then Cervelo would mail us a replacement fork, which we installed on the bike and then called the customer. With the shipping, it was pretty close to a week for each bike. There are a lot of Cervelos in Indy. At one point, we had 11 Cervelos hanging from the ceiling for the recall (some were also in for broken frames). That grouping of 11 bikes added an extra week to the fork recall time (Cervelo got overwhelmed), plus took more time for us to get them all done while still trying to make money by doing profitable repairs. At one point, I think they ran out of forks.
SRAM's parts are made in Taiwan and China. Lead-time is 4 months. If they ran out of Rival shifters during a recall, it could be up to 4 months before more came in. That would suck.
I think this way is better. For me, it's a one day turn-around (SRAM warranty is in Indy). You can bring your bike in early in the day and I can have it fixed and ready for pickup the next evening. If you're far from Indy, it might be 3-4 days (although a lot of shops will use in-stock parts to fix you up and just replace their stock with the warranty part).