@Just_Pierre I don’t know about future releases, I don’t work at Polyend. 
Here in Backstage there a was a mention somewhere about MIDI fixes coming in the next release but it was in a very specific context: Using MIDI side of Play to control and send to DAW.
If you are initially interested on the Play and you are not missing anything specific upfront… maybe you just try it? The Play has very powerful MIDI capabilities, see for instance Turning the Polyend Play into a Mini Midi Station. For almost every young product you will find talk about more features and fixes in the next release, but what matters is whether you find the product interesting here and now.