Yep; I'm going to talk about the scene where Sasuke sends a bird to Sakura with the note Congratulations.

Since Sakura's birthday was near, some assumed that Sasuke had sent the message as to express his felicitation on her birthday. I thought it was weird; I mean, why would you congratulate someone on her birthday? On such ceremonies people greet using the term "Happy birthday". So, it's quite strange to use the term "Congratulations" on such an occasion.

I also saw some posts that said it was to congratulate her for her jounin rank? But she had been given the role of jounin about two years ago. Why wouldn't he have sent it sooner if that was the message's intention? Yeah, better late than never, but it's awfully suspicious. And why on, Naruto and Hinata's wedding of all times? I'm confused, but whatever reason, I didn't believe the message was meant for Sakura.

And, more importantly, let's pretend that note was for Sakura - so then, is Sasuke not aware that it's Naruto and Hinata's wedding?

I think that Sasuke sent that letter to Sakura because he trusted her to give it to Naruto. It makes more sense if you think about it, rather than assuming it was for Sakura. What do you guys think?