This issue persists in Build 3126.
In my opinion, the original poster was correct. It's intuitively wrong to provide a 'select line' command and have the result appear as 2 lines in the status bar. The issue here is that ST3 moves the cursor to the following line when ctrl-L is typed, regardless of the cursor's starting position. This seems wrong to me.
In Vim, if I select a line (using V to enter Visual line mode, the common way to select the current line), Vim reports 1 line selected. if I move up or down, lines are added / removed appropriately.
Someone will no doubt point out to me that Vim is a modal editor: I don't think this changes the fact that any reasonable user would expect 'Expand Selection to Line' (the command name shown in the menu) to do exactly that, and not move the cursor beyond the end of the line.