While watching the 2018 series, keep this in mind

There are fans of Doctor Who and our stuff generally who, sadly, will push through the darkest things through fandom , and there are people who aren't even fans (Nazis, White Supremicists, homophobes and good old fashioned misgonists) who will intersect themselves into fandoms to use it as a platform to spread their beliefs and taint the younger generation and others.

You see it in comic book fandom, sadly - where people push a narrative that Marvel is focusing too much on the younger diverse heroes kids (who are a great jumping on point for new readers), despite the younger kids existing in their own bubble away from the adult heroes and Marvel even had to address it in a video for promoting a upcommiong event.  Or with shakeups with like Amadeus Cho taking over the mantle of Hulk and with Bruce being dead (despite everyone knowing how comic book death works and Bruce's return inevitable due to the MCU) or Riri Williams and Tony Stark (where she isn't Iron Man and her story is all about how her actions as a hero will affect Tony when he returns) or Thor.

I'm not saying these changes weren't going to cause a stir - they were - and people have every right NOT to like them - but there are people for nefarious agendas who will use that stir to lure the young to re-enforce some very dark agendas or use it to tear down these characters because their people of colour.  They'll focus on why these new characters are attached to existing legacies, rather then being new characters in their own right, when they know that the comic book industry isn't in the best of shape right now and can't push these characters that way.  Sometimes this is out of ignorance, but a lot of it is designed to re-enforce their agenda.