Update on the situation at work. I had the meeting. Due to scheduling conflicts it almost got pushed to another month from now, but but was pretty gun ho about making it happen so we had it yesterday with just a few people. Over all the meeting itself went well but there was some discussion about it, as it happens one of my coworkers who is queer is very pro HP still and while hating Rowling with every fiber of her being still supports the series. We talked for a while about how to present the information to the office in the best way, and some debate of "do we want to get in the way of people's joy came up." A hypothetical was even put forth about "what if a trans friend of yours still finds joy in the series but doesn't know about Rowling, do you tell them?" At which point I said yes to both.
People should know what's going on, so they can be informed and decide on their own whether they want to still engage with a series.
Anyways, the conclusion was to write a email explaining the situation and once it gets approved send it to my office. That way people can choose to read and engage with the email on their own time and privately debate how they will handle it. I felt this was the best way of doing it because people who were going to ignore the topic can continue to do so, and there should be less push back on "why are we taking time away from the meeting to talk about this?" from the assholes in my office lol.
I wrote the email draft and sent it off to the team for review, so we'll see how that goes.
Additionally, my boss sat down with me to discuss it and made it clear that I am 100% valid in my opinion and stance on things, but I also can't be critical of others and need to let people do what they want. She approves of me informing others, but doesn't want any issues in the office because people disagree with each other. I also have to accept that people will probably still talk about the series in the office, and I can't tell them not to talk about it.
So basically my conclusion is that this whole thing has been a failure LOL. While I'm being told my feelings are valid and I'm allowed to educate people, I'm also told to respect "whether people continue to enjoy this series or not" but honestly this is what I should have expected.