As noted earlier, the decision to bring back Luke Harper was not a last-minute decision but was a very late decision.
Dave Meltzer reported on Wrestling Observer Radio that the call to Harper was made on Friday and it was because Erick Rowan needed a tag team partner for a planned match.
Meltzer also said that the current plan is for Harper and Rowan to team up in a match against Roman Reigns and Daniel Bryan in the near future. I would assume that this match would take place next month at the Hell in a Cell pay-per-view.
Harper helped Rowan defeat Reigns at Clash of Champions. Harper hasn’t been seen on WWE TV since August 2018. He was cleared from a wrist injury earlier this year and wrestled on the Worlds Collide show during WrestleMania weekend. He was also part of the WrestleMania battle royal and a dark match before SmackDown Live a few days later but Vince McMahon made the call not to use him again. That is until a call was made this past Friday.
Many in the company believed that he would never be back and that he would jump to AEW when his contract expires sometime in March or April. That could still be the case but it looks like he’s going to be in a storyline with Rowan at least for the foreseeable future.