The Reddit logic about the invite makes sense alright. Remember when Meghan said she would break up with Harry if a statement was not issued about racist press treatment. He did as he was told. Now the same is expected from the Palace in requesting that a similar statement be made about the racist remark. Meghan wants an acknowledgement of there being unconscious bias and better yet wants the public apology they've long been talking about. Harry teed it all up with Tom Bradby saying they never said racism but that it was unconscious bias. It was the evil press who drove a wedge between them by saying they accused them of racism. He had it himself, Meghan saved/educated him and he wants to help his family. The heroes and the victims at the same time. So with the invite gone out another request for this statement/apology was made conditional for her attending. The Palace gave a firm nope/take it or leave it/GTFO. Meghan blinked and retaliated. A statement made about nonattendance. The Palace acknowledged that news quickly.
Now in desperation there was the leak of the letter exchange done to limit the damage and give her target audience in the US all the background about why she is not attending. Effectively, I hold no grudges but I got no satisfactory response about what Harry and I know was unconscious bias and, taking this into account, I won't be attending. It is done to aggrandise on being principled but also stick the boot in i.e. they will never change, I tried to help them, they were mean and cold to us, waagh etc. What makes them so laughable is the remark about her living in the present while covertly dredging up material from years before. All this song and dance knowing if they did go it would simply be a copy and paste deal of the Jubilee (show up, get glared at, Major Johnny keeping an eye, second row if they're lucky, mini van to Heathrow, bye bye). They can't monetise that so they've kept on brand as "Victims" instead.