I actually think you're mostly right and the responses trying to nuance this are kind of missing the forest for the trees. Yes, context matters. Yes, some people have trauma around money. But that doesn't change the basic fact: silence about money is how exploitation continues. Full stop.
I grew up working class and this taboo nearly cost me everything. I didn't know what middle-class salaries looked like. I didn't negotiate because I didn't know I could. I didn't know my friends' families had money because nobody SAID anything. That silence kept me isolated and broke. The moment I started asking direct questions and people answered them - that's when I started understanding the actual landscape I was living in.
Here's what I want to say to the people worried about "making it awkward" or "forcing vulnerability": someone's discomfort with knowing their friend makes more money is not a good enough reason to perpetuate a system where people get systematically underpaid. That discomfort is actually the POINT. It's the discomfort that might make someone actually DO something about inequality instead of just feeling sad about it abstractly.
Your friend didn't ask everyone to suddenly dump their financial trauma. They just want to be able to mention their job offer without shame. That's the bare minimum. If your friendship can't handle that, the friendship probably wasn't built on anything solid anyway. I'd rather feel uncomfortable with my friends about money than comfortable in ignorance.