New model in the US with low demand right now. Vendors are not going to do the R&D, prototype, refine, manufacture and then sit on inventory for a year or so. Unfortunately, they will wait until the demand picks up. Soon I hope.
Personally I wouldn't risk it. I find it frustrating that these trucks can't handle the weight without the braces but so be it. Ford is addressing it in future builds and hopefully they'll do the right thing for the early adopters.
Tough question and decision. If you're not into rock crawling or extremely difficult trail riding then the RR is the way to go for many reasons that have already been mentioned. If there is some serious offroading in your future than I would lean toward the Bronco. If you're after better...