Hi Francesco, nice that you help people!
Actually i think that no one could guarantee the continuity of Mendix and the (free) apps on the long term. To be honest what if tomorrow Oracle/SAP/Microsoft etc will buy Mendix and enclose their services in their current services...? Of course there will be a transition period, but at the end you are working with a non-open source platform....We can hope that they will make plans for the existing Mx (free) customers....