To be fair that reply is an insult to the intelligence. A load of the seats that are released late are right in the home fans area and nothing to do with the away allocation
The reply you just got regarding the Forest game is also the same.
The reasons they give are understandable, even if we all know not quite true. Take Bristol for example. Yes, we might not know till nearer match day how many they are taking, but it was surely clear more south stand seats could have been offered here.
Anyhow, I have asked one more (my final question) question on ATC, as there are still the prime south stand seats behind the goal in the eastern half (closest to the away fans) which are never offered for sale unless literally everything else has gone. The stewarding policy/sterile area argument does not fit here as ticket holders from the western half of S1G are free to spread out into these seats.
Even with a massive piece of tarpaulin and a line of stewards, there was still 6 rows (150 plus) seats here - there is no reason why these are not made available the day they go on sale.