Joseph Kelly has interacted a bit with that question today. He doesn’t answer it so much as point out the wrong way to approach the discussion. I agree with Joseph that defending a list of theological implications of Adam NOT being historical is not an intellectually honest way to approach the issue.
I posted on a similar issue a couple of years ago: Using the NT to validate OT historicity. Does the fact that a NT writer mentions an OT character support the historicity of that OT character? Not necessarily, in my opinion.
Read Joseph’s post if it’s an issue you’re interested in.