Inclusiveness is something that is more important in a community than anything else.
While it may be a few months late, I'm glad to see a new thread on this subject. Everything that follows here is from someone who has minimal involvement in pride-related matters.
I looked over the O5 thread on this. Firstly, I'll echo 
Joreth that we should not have the pride banner permanently on core pages. Correction; in my opinion, we should have nothing like this appear on core pages permanently. I say that because the SCP Foundation is an writing site, not a propagation/advocacy site, even if it is for something as important as showing that we are all-inclusive. Replacing the SCP logo with the pride one on core pages annually for June makes sense, as it is a way of showing that we support the LGBTQ+ community. However, having it up all year will break more things than it would make I feel. Same logic can be applied if we did anything else of the sort.
As for actually celebrating pride month, I honestly think a Pride-themed contest could be interesting. How we would go about that is a good question, but I think by having something like our successful Nightmarefest contest, but instead being related to pride, would definitely be something to put into our scope. Aside from that, I think replacing the SCP logo with the pride version in June on core pages should be done again next year. I don't see how its emersion breaking.
e: I noticed 
Kothardarastrix's post, and I think the interviewing icons on LGBTQ+ authors would be something else to consider.
A couple of words on the "banning people who show aggression towards LGBTQ+" (or any other groups). Rule zero on the site is don't be a dick. Actions like the aforementioned aggression are in direct violation of this policy, and should channel through the same way harassment or bullying is channeled through. Which I'm sure it already is.
Also nothing that yeah, people saying "it ruins the immersion" or "too political" should be approached by staff with disciplinary action.
These are just my thoughts anyway, I know they may not be strictly related to the thread's topic, but I wanted to put my opinions on the O5 thread in there.
