Best there could be is a competitive upgrade or trade-up discount. As I understand it, Elation and ADJ are tied together, they aren't run by the same people.
Technically speaking, ADJ is a competing brand with Elation and vice versa, despite the fact that the two companies are catering to different markets. ADJ is to the small guys and small budgets, where Elation is dealing with those who have more to spend, but also need more bang for that buck.
A product not being "constantly upgraded" is NOT the same as being frozen. Frozen is "Dead". ADJ can't continue to keep adding features to MyDMX without it incurring additional costs for current owners, and increasing that intial cost to own purchase price for new users.
Sounds to me like the product is in an ongoing support position. Just because a new version isn't coming ot doesn't mean the product is frozen.