Is this the the equivalent of "new lightning bolt" effect due to rule change on planeswalker damage?
Let me explain below the question and confusion.
The new Buy-a-box promo, Firesong and Sunspeaker, has an effect that spells out “target creature or player”. Is this the first card where we have to remember that the effect excludes planeswalkers, i.e. we don't replace the text with “any target” since it's printed after the planeswalker damage redirection rule change?
Channel Fireball's article Understanding the Dominaria Rule Changes and Sagas says:
Now, imagine they print a card like this:
New Lightning Bolt
New Lightning Bolt deals 3 damage to target creature or player.
This card explicitly excludes planeswalkers, but, if you don’t know when it was printed, you have no way of knowing. If New Lightning Bolt and old Lightning Bolt are both in your hand, they’ll have the exact same printed text, but one will work very differently. It’s not going to confuse any established players, but I can see how it could confuse someone who’s not already enfranchised.