Sure, but it seems you are looking for (monocular) SLAM?

I was thinking more so to add 3d objects to previously recorded drone footage.

Would SLAM be the best option there?

SLAM would be to build a 3D model of what you filmed with a drone.

Adding CGI to drone footage doesn't require that, and is absolutely something Blender can do. Look at its motion/camera tracking features.

This video is awesome for what it sounds like you're trying to do.

https://www.youtube.com/watch?v=lY8Ol2n4o4A