Lehman Bros.
Salomon Bros.
Warner Bros.
Brooks Bros.
Etc.
Salomon Bros.
Warner Bros.
Brooks Bros.
Etc.
No, but it would be unusual. You don't hear people using a term like "crypto brothers", for instance. "Bro" carries a different connotation, and it isn't a positive one in this example.
I don't think it is simply an abbreviation in this case.
In my experience, it does have different meanings.
One usage makes me think of: "friend", "close friend", "homie", "my guy", "dude", "someone I trust", etc.
Another usage is: "immature", "douchey", "fake", "asshole", etc
Understand that bro also has a pejorative connotation in some context, but that is not the case here.
If the quote was "we are operating as a fking unlicensed securities exchange in the USA brother." how is the meaning different?
I can see that they have slightly different connotations like thanks versus thank you, but that doesn't mean it it's no longer an abbreviation, which is what the parent poster was claiming
But it ceased being used that way a while ago. Now, it's largely used to indicate a certain personality type (at least in my neck of the woods).
It is still often used by many people for friends (like the quote in the link), with the original meaning.
Some people also use it as a pejorative, usually against people they don't know or like.
I think it is an error to think that the second usage the only one, or even the predominant connotation. I would guess a small portion of english speakers hold negative opinions about "bros", and the concept isn't even on most people's radar.
How often does the word bro get used, and in which context? I would guess that bros use the word in the positive sense more often than other people spend talking talking about bros in a negative sense.
If someone claims that there is only one meaning of bro and that it is negative, I think that reflects more on their social bubble and social leanings than reality.
Dutch Bros.