The MLB100 can be upgraded to the Skytrax200, refer to:

https://www.avidyne.com/avidyne-announces-skytrax200-dual-band-ads-b-receiver/

PIlots should work with an Avidyne Dealer to have the unit sent in for the upgrade. The above article provides an estimated cost. 

https://www.avidyne.com/find-a-dealer/

With the changing of products in the aircraft, pilot should engage with dealers/installers to assess the antenna requirements.