Im pretty sure they would've told us if there was any split screen (even though they dont communicate much here xD).
UC3 had split due to 3D rendering twice if I am not mistaking. TLOU does not have it so I wouldnt be shocked if TLOU did not have split screen.
Not to mention whenever me and my friends wanted to play UC3 split, 1/4 of the screen being black really is annoying and turned many of my friends off. I can see ND probably seeing that the amount of splitscreeners isnt worth the extra trouble.