Question about Manually Syncing Mac and iPhone

I have been syncing my devices manually (with a cable) on my Mac for the past few years, and I have been holding onto many songs that I copied over from a CD (a long time ago). I am NOT an Apple Music subscriber, and I was wondering how syncing would work if I were to make changes on my Mac and my iPhone.

For example, let’s say I remove playlist X at 2:00 PM on my iPhone. I then remove playlist Y on my Mac at 3:00 PM (without manually syncing the iPhone before removing playlist Y, meaning that playlist X is still on the Mac).

What would happen if I synced my Mac with my iPhone at 4:00 PM? Would I simply keep playlist X and have playlist Y removed since the Mac was the device that was last updated/edited before syncing?