No, there are no EX cards in the TCG GameBoy game.
Containing every card released in the real Trading Card Game's Base Set, Jungle, and Fossil expansions, except for the Base Set's Electrode and Fossil's Ditto, and including many game-exclusive cards which were never produced for normal play, the game emulated the experience of the actual Trading Card Game very closely. No normal counterparts of holographic cards are included. - Bulbapedia
Plus, I checked through all the decks mentioned, and there are no EX Cards in them.