The difference this time is that the Doctor's queerness isn't just a side note. It's central to the story now, undeniable in ways that bigots watching back home can no longer refute, no matter how much they might try.

That's the guts of the article, since it acknowledges this has been in place since Russel T Davies' first season as lead writer in the mid 2000s. The part I liked about it is the classic sci-fi method of making it seem absurd to the main characters that the people in the past would think this is scandalous. Other than that it was an all-round good episode with a fun story.