Hi there,
At this time, there are not any upcoming plans to add EDM support in AtoM. This would be a major analysis and development project, and at this time I don't foresee such support happening in the near future.
In the interim, I think your best bet would be to investigate conversion options. For example, it appears that some research has already been done into converting EAD into EDM - see for example this paper:
This was found after a cursory search - there are likely other tools and articles available. It would also be possible to develop a script or tool for conversion (from EAD 2002, or even CSV) without modifying AtoM at all, which would likely be more cost effective.
Sorry, and good luck!