I'd probably drop the older one off first so the younger can see them go to the bigger kid school--it will make what is happening more concrete and real and they will process the change faster. But also, after a week or two it probably wouldn't be a big deal to the 2 year old to go into school on their own anymore because it will be the new routine and it probably won't matter as much which order you drop the kids off.

My older kid is leaving current daycare for elementary school in a week, but my younger kid will stay at current daycare. The younger kid has been going to daycare everyday for 2 months with no crying because the older sibling goes together, not in the same classroom. I am a bit worried when the younger one finds out the older one is leaving him behind to attend a different school. The younger one is just turned 2.

Is it less drama or more drama if I drop off the older one first and then drop off younger one next, and pick up the younger one first and then older one Next?
I need to walk both kids to the front door for drop off at both locations, and they are 5 min driving distance away.