IIRC, the primary reason we're even going with this route is that one of the primary things stabilizing the arctic permafrost was actually the presence of snow-wading megafauna changing the rate of heat dissipation in high-wind tundras. So, they're trying to bring the wooly mammoth back to try to keep more permafrost around.

ETA: Here's the company actually saying this is the primary reason for doing it. Its about restoring the biodiversity loss from humans being an all-around virus for the last 10000 years.