According to the Wrestling Observer Newsletter, the reason the WWE Roadblock match between Brock Lesnar and Bray Wyatt was changed to a handicap match is because Bray is working with a “pretty significant” back injury.
It’s unknown how long he might be sidelined for, but the injury is a possible reason why the match was changed to include Luke Harper, and Bray never tagged into the match. It was previously reported by some that the reason the match was changed was because WWE wanted save Wyatt vs Lesnar, a match originally planned for Wrestlemania 32, for after the big event in Dallas. It now becomes evident there were other factors at play in that decision.