Look, there's not much point in us arguing, but I'll go ahead and point out where you said stuff that I found dismissive of OP.

Going to a exotic location should be a shared experience together

Why? Why is this a must? I don't understand this at all.

That's dismissive of how he thinks & feels. A LOT of people (on /r/relationships as well) feel the way he feels. That big, exotic trips are to be done with your SO. I don't feel that way, you don't feel that way. But it's not unreasonable to think that way. Most people don't get tons of vacation time, so exotic trips and vacations are special times with your SO.

I'm completely surprised so many people think your wife is being an unreasonable bitch about this... when I don't think she is at all.

Also dismissive of how he feels. He's not saying his wife is an unreasonable bitch. No one is calling her an unreasonable bitch. She's just been very callous towards her husband in planning an exciting vacation explicitly without him, and without his knowledge.

You can still give her an amazing birthday! Just plan it around her trip with her friend. It doesn't have to be on her exact birth date to be a great experience!

Apparently for him, it does have to be on her birthday to be a great experience. That's what they'd discussed on his 30th birthday - that they'd generally be doing something big & fun for her 30th birthday.

For you, it's no big deal to not be around your SO on 30th birthday. I feel the same way as you. But OP clearly doesn't feel that way and it's not at all unreasonable, how he feels.

If you read my comment, I said that he should explain to his wife why he's upset, and that communication really was the issue.

Sorry, but in your top comment, you simply didn't say that ... at all.