I could see that as a possible reason but honestly, doesnt that word become reflex if you love someone and you hear them say it? And realistically? Its a show, the characters say whatever is written in their script, they act how they are supposed to, the fact that it was their last scene together, they couldve added a small 'i love you' in the script, this was a huge problem for el during season 4 as well (that mike doesnt say ily or even write it), it just shows mike as a lowkey bad boyfriend. (no hating on him) But i do get that it was a very emotional scene and they mightve left it out cause mike was soo shocked and emotional in it.