Trinity Force on Yas?

Hey all, I recently picked up Yas on my smurf since I wanted to work on a few mid lane champs since it is the one lane I feel truly weak at (relative to everyone else at my elo. I get that I'm silver). I also thought the proper two first items on him were shiv into IE, however lately I have seen a lot of people going shiv into TF. Is this match up based or just a shift in the proper build path?

If anyone can offer an explanation of this change I would greatly appreciate it.