"...we will be re-releasing select old themed items, as well as releasing brand new items..."
It's not just a free for all of all the old rare coming back. The prices will depreciate slightly, but we don't know what's going to come yet, so certain things will most likely still be the same value when this month is over. And I like the fact that people who started later on now have a chance to get things they missed. A lot of people only just joined this summer and have been scrambling to try to catch up, so this gives them the opportunity to get on even footing with the monster traders who've been hoarding rare for months.
A way to keep the re-released items more rare would be to only release them for a limited amount of time. Like, instead of the way that all the themed furniture and clothes stay in the shops all month long, the re-released rares could be in for only the weekend or 24 hours. It's there so that everyone has a chance to get it if they can, but will still be considered rare when it's gone.