What was SLU’s old name?

So I’m drinking at Thunderbird Tavern on 15th post baseball and this kinda dive bar guy started going off someone for calling South Lake Union SLU and said when he was a kid it was the Cascadian neighborhood… me being the post baseball kinda drunk cell phone user I am found a Wikipedia entry saying the entire southern tip of lake Union is the Cascade neighborhood (https://en.wikipedia.org/wiki/Cascade,_Seattle). I’ve never heard of someone say they live in Cascade, this is blowing my mind! Why does everyone just call that SLU now?