Lance Anoa’i was reportedly signed by WWE last year, but his debut was delayed, possibly due to injury. Since it's been months with no update, SummerSlam might be the perfect time to introduce him as Roman Reigns' surprise partner.
In 2019, Reigns had saved Lance during a RAW segment, so there’s storyline history. That connection could be used to justify his sudden appearance. With the Bloodline needing backup, Lance’s arrival would add depth to the family saga.
It also gives WWE a fresh face from the Anoa’i lineage to push post-SummerSlam.