Oil pressure goes up with RPM, rule of thumb is you should have 10psi of oil pressure per 1,000 rpm.
Ford uses an oil pressure switch on the engine, an on/off switch, so no real oil pressure info is available to the driver, even with working gauge.
The switch is off when oil pressure is below 6psi, on when oil pressure is above 6 psi.
You should have 8 to 10psi oil pressure at warm idle.
After highway speed the oil heats up and thins out a bit, so when you slow down to idle the oil pressure can drop a bit more than normal, but not usually under 6psi which is what sets off the Check Gauge light.
What oil are you using 5w20 or 5w30?
I would stick with 5w30 year round on the 3.0l
5w20 could cause your issue.
Check the fuses for cruise control, if buttons were bad it could have blown