If you are referring to E-Eon stealing your amiappstore idea, then i dont think so.
After all, I had idea for ami appstore already 2005, and that was based upon seeing wildgames wildcoins system, from which i thought my own version of it for Amiga (by other words, was copying the idea with own additions), which was more of a half way from wildgames system and todays appstores. However, since in these last 10 years i havent got any games released (which is bit embarassing), my plan never came to reality (or even got started rather). And after Apple and Android appstore came to be, im pretty sure theres couple of hundred more or less serious ideas about amiappstore existing in peoples heads.
So, no. I doubt they stole your idea. they just got it just like you did by seeing those other appstores.
But so far it seems your idea seems to be having more unique ideas, although i think it is also riskier in terms of succeeding. Amistore is somewhat safeplay. Nothing big, but quite sure bet.
I see that similar...
Finally the developers will decide where to put their software. It seems that Amigakit/A-eon support 3rd party developments, I could guess that they try to get some of the software exclusive on their app store. But other than that everyone can decide where to sell or distribute what he creates. I only hope that this platform will be open for news regarding new software even if it sold on the other store and not only this one.