I spent almost 90 minutes with the support team today. There is currently no solution to the problem. They are not able to assist until Quickbooks fixes the problem.

Just to summarize the problem....

If you "invite" a contractor to sign up through Quickbooks Self Employed, so that they can see their pay stubs and 1099's, they receive a link via email. But that link can expire. Once that link expires, there is NO WAY to resend the link. There is no way at that point for the contractor to get access to their pay stubs and 1099's. 

I'm not saying it's hard to do, I'm not saying it's complicated to do. I'm saying there is NO WAY for the contractor to get access once the original link has expired. The invite email cannot be resent, neither by me (the user) nor by the Quickbooks support team.