Perhaps American thing, but yes 52/53 with Joker can be referred to as a deck of Poker cards. Especially in the context of Pokemon cards it gets confusing to say playing cards instead of poker cards.
If someone is interested in a poker set from December 1996 there is also this lovely alternative (yes I’m sharing my own thread lol):
www.elitefourum.com/t/kagemaru-himeno-poker-set-mini-binder/32092/1