I had a bit of a look into this a while back mate.
As far as i can make out the stadium is funded and paid for through Everton Stadium Development Company, which is wholly owned by Everton Football Club.
Moshiri owns Everton Football Club, he could conceivably sell the club and not the stadium, but then at the moment he could sell the club and not Goodison, so no difference really - any owner could do the same - if someone else was willing to do that deal. The other thing is there is no incentive for a buyer to do a non favourable deal on assets or buy a football club with no where to play or without a fixed asset to generate revenue and increase its value.