If I had to guess, the complication they ran into was that they realized that they didn’t actually have an unnerfed version of Power Word: Shield or Holy Smite in the game. Since the text changed, they’d need alternative copies of these cards if they wanted to restore the puzzles to the original state. They can’t tell the game client to display a card that it doesn’t know anything about, after all. Therefore if they didn’t want to make a new puzzle, this would have been impossible to hotfix.
However, the data of the latest patch reveals that these cards now exist:
[Holy Smite][CS1_130_Puzzle][62850]
[1 Mana, Free Spell]
Deal 2 damage.
[Power Word: Shield][CS2_004_Puzzle][62917]
[0 Mana, Free Spell]
Give a minion +2 Health.
Draw a card.
So while there hasn’t been an official word yet, and it’s still not fixed quite yet, they have recently cleared a roadblock in getting this resolved. It can now be dealt with in a server side hotfix, so I would expect results Soon™.