I think she'll go. It's a win/win for her. She gets new photos to document her Royal connections. If she gets booed/heckled or worse, she can claim more victimization. If she doesn't, she gets to preen about how special she and Harry are, how valued their mere presence is to the BRF.
Archie is a true mystery. I think she was pregnant. Her face changed a great deal. Her annoying belly cupping throughout the entire pregnancy, that felt like it lasted a decade, only to now never show him, or hold him so awkwardly when she does show him, only makes sense if you believe she is severely Narcissistic. Being pregnant does give one a lot of attention from most people. I remember having strangers constantly talking to me whilst I was pregnant, and the really gross encounters where randos actually tried to touch my bump. It's always about her. It doesn't feel like she really cares all that much about Archie as a person, only in how much she can monetize him with the BRF in negotiations, or making bank from photo ops.
I'm really more disappointed in Harry. Mostly for how his behavior is an absolute show of disrespect to his granny, who stepped in a lot after Diana's death. Particularly because of Diana's death, you'd think he'd be extra close to TQ and Prince Philip. It doesn't track for me that he, who is still so traumatized over the loss of his mother decades later, is galavanting around the world without his only child. Makes no sense.
I wasn't close to my family before I became a mother. However becoming a mother made me swallow my pride, and open myself to being a part of their lives again. Solely because my children deserved to have all the support and connection they could get to their grandparents, aunts, cousins, etc. No child should be kept away from close knit families. It's the adult thing to do. George, Charlotte, and Louis are evidently happy kids that are close to their cousins. That experience is priceless. I'm shocked that Harry has so easily removed his child from any chance of having those kinds of relationships. Putting aside the grown up dramas between everyone, the kids deserve to have that closeness and the fun and memories it gives.
Archie feels less Royal to me now specifically because we never see him with Prince Charles or the Queen. You'd think Meghan being such an opportunist would be shoving him at them just to have the documentation of it all. After all, she can't stop herself from reminding everyone that Harry and Archie are Royal born, super duper important people, that will always be Royal, part of the Succession line, vitally need protection, etc.