I will take a punt and say that the reason (IMHO) is that if...

I will take a punt and say that the reason (IMHO) is that if they didn't come out of suspension now they could only issue shares via a prospectus (because of being in suspension longer than 5 b/days). So I reckon ASIC and ASX were drilling down into the terms of the supposed deal and had a few gotchas and if CDB didn't cancel they would find it very difficult to come back onto the ASX platform.

IMHO I believe ASIC and ASX are onto their case.