Will a metal disc affect future mri scans and there ability to show nerve impingements in the same area?

Yes, it will: cause an artifact that limits visualization in the vicinity. The extent depends on the type of device and the type of scan. Usually, artifact from disc prostheses do not obscure the nerve roots or thecal sac to a significant extent.

Likely: Depends on the kind of metal and the exact placement as they can cause distortion and artifact of the images.