James Cameron and Billie Eilish film

I was curious what box-office observers' take was on this match-up...I always like to try and figure out the real story behind a deal. Given Cameron usually is about Avatar right now, why make this concert film? Is it a way to bring in some revenue during some downtime for his company? In other words, offset some of the Avatar costs that may have been incurred directly by him? Is he testing out new 3D tech? To the best of my knowledge, beside some ocean stuff, he hasn't done too many documentaries or concert films (but perhaps I am wrong). Thanks for any insight.