Yeah not absolutely every meme/slang listed might be originated on 4Chan. TLDR seems to have originated or at least popularized by the SomethingAwful forums, which together with ebaumsworld could be considered the parents of 4Chan (with cross-pollination by Newgrounds?). But 4Chan was the crossroads of all these memes coming together, germinating and spreading to every other site shortly after.
I’m extremely skeptical of the first use of “TLDR” coming from 4chan specifically.
Yeah not absolutely every meme/slang listed might be originated on 4Chan. TLDR seems to have originated or at least popularized by the SomethingAwful forums, which together with ebaumsworld could be considered the parents of 4Chan (with cross-pollination by Newgrounds?). But 4Chan was the crossroads of all these memes coming together, germinating and spreading to every other site shortly after.