I remember someone started a thread about the acquistion and the developer actually posted and said they plan to continue MPQ for a few (?) more years. Some other F2P Marvel games can't even smell 2 years, like Marvel Battle Lines
If they stopped releasing 2 new characters every month they would be able to free up resources to work on half the things on your list. But they're unwilling to do that either because it brings in money or they're just complecent and let things run on auto pilot. Without any insider knowledge or official communication we can only speculate but my feeling is there's a bit of truth from both and management issues as well.
It takes more people than you think to run any kind of business. People have talked about the game shutting down since the beginning and it’s still here. Don’t worry, it’s fine. If it makes money, they will continue.
I would only worry if the player base shrinks and you start seeing “going out of business” sales.