Should I replace my MacBook Pro memory ram after repairing it?

Hello! Ok here's the thing, last February while working on my MacBook normally, I stared to notice some failure in my screen, like screen corruption, vertical lines and the screen been parted and tilted to left and after pressing bottom (and not reacting) the screen went full blue. After several attempts to make it reacts (by pressing any bottom) I had to force it to shut down, and after that I couldn't turn in back on. I took it to a local apple certified store and found out (after doing online research as well) that it was the graphic card (not sure how you call it) and that it needed to be replaced. However 3 weeks ago I took it to the Apple Store in new York and the fixed my MacBook, bringing it back to life, they had replaced the logic board as well as the memory Rams, all for free (given the fact that it seems to be a factory failure).

So, now that I got my macbook back working, I realized that apple replaced my 8gb ram (each) for a 4gb ram (each), I used to have 16gb of ram, now I have 8gb, now, and here's comes the real question, should I put my 8gb rams back or would it be a false move to do? Considering that in the detailed report apple gave me after the repairing, it said "memory module (RAM) - issues

Just wanted to hear your recommendations on what should I do

thank you!