Hello Brooklin and WELCOME!
Yes you can get discounts. Apparently, you have to go thru the offices in Michigan to get the information. My dad is retired and I called the retirees office in Oshawa and they don't have any info on it.
When I worked for EDS, all I had to do was show my id at the gates at MK to get a discount off the daily admission.
If you pm me your email address I will send you the "old" discount documents that someone else here emailed to me that worked for GM in Michigan.
It might work out the new tickets are a better discount.
Marilynn