Without doing much research but i can see this being a clever move by Moshiri
First, i seriously doubt that he will sell his shares on the cheap to help the club (as being reported), he will make sure he gets all his money back, even if it will take years, even if his children or grandchildren end up being paid.
Second, he might be using 777 as a tool, as a service, they will be the new face of the club, we will no longer be owned by an Iranian billionaire the partner of Russian oligarch, we will now be owned by American investors.
We might never find out who those "partners" are, Moshiri will disappear from the public eye, the old regime will be removed (Kenwright will be out), new board, CEO, Chairman. Money will be available as needed (already mentioned in the club's announcement that the stadium built money is now secured), nobody will knew the "source" of the money, it will always be "partners"/"investors".
The premier league and government/authorities will have an idea about it and will allow it to happen.
The fans will get what they wanted (Moshiri/Kenwright out), authorities will get what they wanted (no longer owned/linked to Russian oligarch), the club already improved the financial fair play thing with the last 3 years of fire sale and wage reduction.
Is it ethical? No, should we care? No
Is it dirty money? Most probably yes, Should we care? No