Defender does not discard at the end of opponent’s turn if the pokemon with defender is not damaged or knocked out.
If a Player A going first uses Pichu’s “Playground” attack, and player B chooses a basic pokemon with the effect of the attack, player B is able to evolve that pokemon on their first turn.
" If my opponent uses Pichu’s “Playground” attack on the first turn of the game, and I am going second, can I evolve the Pokemon I put onto my Bench with “Playground” since I did not put them in play on my turn?
It is a basic game rule that neither player can normally evolve any Pokemon on their first turn of the game, even if they are going second.
Source: PUI Rules Team (2010-02-04)"