AGREE! When ripping wide 2X SYP, especially the stuff grown real fast is going bow and twist. It's not the moisture, it's the grain. You don't want to wait for everything to dry and then discover you have 30% waste after you rip them and then need to wait for the replacement to dry.I'd go ahead and rip them now. Get that internal stress relieved, then sticker them and let them freak out for a month.
5" is a very thick top!
FWIW, right of wrong I made a 2' thick, 30" X 144" top from SYP and didn't let it dry and never moved/checked. I used biscuits to help with quicker glue ups. I did (2) 15" wide section, let the glue dry, run it through the planer and drum sander then glued the two smaller pieces together so I only had to hand work one joint.