Why wouldn't the new owners want to take on the perfectly serviceable mortgage? It wasnt that that took us under, it was the debt with the Bank (basically). If the new owners can clear off the other debt and leave themselves with the stadium mortgage only, they need to pull in 15k per week to cover this (as stated on here many times). If they can bring in gates like that - and why not, all the anti-Lowe fans will flood back, surely - they will be in a better position that any board for the last 5 or so years.
Aviva will know how the previous boards set out their stall in terms of payments and ring fenced monies and will know that as long as there is a club to play at SMS, they stand a really reasonable chance of getting payment in full each month.