Once you unlock a residential district, you just need to go to the aetheryte for that area to check all the wards and plots. Nothing tells you when it's going up for sale only that it is for sale. Once it's up for sale though there's a RNG timer applied that will prevent people from buying it until it ticks over. The timer is completely random and can stop at any second.

As for the turning off of demolition, that was back in October of last year. They just turned it on again recently. Within this week will be the first 45 days since reactivation, so some houses should get demolished.