Ok. Hear me out.
Disclaimer - proposing at someone’s wedding or announcing a pregnancy at someone else’s event, if you don’t have the explicit permission of the hosts, is never ok.
I would have been overjoyed if someone got engaged at my wedding. I would have been so insanely happy if someone had announced their pregnancy at my baby shower. I give zero fucks about having to be the centre of attention and like, it was MY wedding and my shower, so it’s right in the title that it’s all about me. In fact, just as I’m flattered to be asked to be in a bridal party, I’d be flattered as fuck if someone picked my event to announce something huge- I would feel extra included in their massive life moment. I would feel like I was important to them. My ego would be purring that they were going to have my event be part of their story forever.
A wedding is your special day, yes, and ultimately what the bride and groom wants is what should happen-period. But weddings are also about family and friends. The people you invite were a part of your life before you met and fell in love, and will be there watching your marriage grow. And you will be there in the same way in their lives. A wedding is like a family reunion. It makes sense that when you’re celebrating, you should celebrate all the things while you all have a chance to be together.
I think it would be better to just always ask first, respect the answer, whatever it may be. Don’t be a psycho and just do a surprise or do it when the host says no. But the blanket opinion that it’s tacky or rude and never ok, I just don’t agree.