Towards the end of the match, Reigns told Paul Heyman that something "is out." It sounded like he may have been talking about his shoulder popping out of the socket but the photos below appear to show that he may have torn a muscle. This may also explain why the match had a flat ending.
So far, there has been no word from WWE on what Reigns's prognosis is. Hopefully, it's not as serious as it looks in the photos below. After Reigns won the Undisputed Universal Championship, he struggled to hold one of the titles up but he did manage to get the bad arm up at the end.
As for what is next for the brand titles, the plan is still to have a main title for each brand. It's not clear yet how the title will be introduced but as of now, there is one men's WWE title.