iBeacon and Eddystone are open protocols, sure. Meridian does use the iBeacon protocol.
However, Meridian is a lot more than simply an implementation of the iBeacon protocol. In the same way that Apple restricts its software to its own hardware to improve performance, Meridian focuses its efforts on Aruba Beacons hardware to make the strongest possible product.
In this case, this isn't a question of whether or not something is possible. It's a question of where we're choosing to focus our time, energy, and creativity.
Thanks for your question!
Shawn