Thank you. But that still indicates I was wrong - the possible solutions appear to be essentially the same - even if particularly different. I was surprised to see "slave" as an illegal guess.
But it would appear that the difference in previous solution: stairs vs royal(I think ?) might just be slightly different word lists for the solutions... I thought there was much more of an edit.
They changed some obscure and offensive words initially, but there have been recent news articles around days where people had 2 different solutions to the same puzzle.
Initially I suspected that this was NYT watching for how unusually difficult words play out and then changing the answer on the fly to be a simpler word. But I think in reality these were the same changes they made shortly after the acquisition and somehow people have the old JS file cached locally.
But it would appear that the difference in previous solution: stairs vs royal(I think ?) might just be slightly different word lists for the solutions... I thought there was much more of an edit.