As you say we can only guess (although it's a probably a good guess) that SISU are having a financial nightmare at Sixfields and that ACL are facing a large decline in revenues without us. We don't know as a fact that either of them are, as they haven't published and indeed I think don't yet have to publish accounts covering any of this season yet.
One of my concerns is that ACL weren't bluffing and actually can survive (even if it's just above break even) with out our club and don't need to get us back. Suppose we get to the end of 5 years and Tim is still looking for badger droppings with the only stadium in sight being Sixfields? If ACL have "moved on" and found (as unlikely as it seems) another tenant for the pitch or another use then we won't be able to go back very easily. What are we going to do then? Are SISU going to resort to the courts to force them to allow us to play at the Ricoh if the new stadium doesn't happen.