I don't think it has changed. Triple click is technically paragraph select and is from the previous carriage return (or start of file in the case of the first paragraph in a file) and the following carriage return, (unless it is the last paragraph of text in the file in which case the termination is end of file}. When looking at a display line, its length is a function of the Font, pitch, and window width so it is essentially arbitrary. The only way I know of to consistently copy a display line is with a screen shot. This works in many windows throughout MacOS/IOS their apps and most third party apps.
