How do you know what decks are limited edition? And ...

how do you know what decks are limited edition? And do we have a list of oop or oop soon decks including oracles?

(wondering if the russian gypsy fortunetelling deck is oop for one)

One way is to check on Tarotgarden. If they have it listed, it will give both oop and limited info.

Decks published as limited edition decks usually bear that description in their titles; & listed or marketed accordingly.

I recall some discussion of OOP decks, but unable to find it.

Where oracle deck questions concerned, recommend posting in Oracle Decks to reach the appropriate audience:

http://www.tarotforum.net/forumdisplay.php?f=63

Alida also has in the product description if a deck is limited edition or not, but I believe they don't have OOP information.

I don't think there is one list of what is OOP (and it would be hard to keep up to date I think) but if you search the Tarot Deck section here for threads on OOP decks or for individual decks, you will probably find the info you need.
When a deck goes OOP I usually hear it here first