FWIW & IMHO:
I have noticed this condition on every TR that I have ever owned, (5), be it garage queen or daily driver, and I have found that using GM Silicone grease, General Mortors part no. 1# 1052863 will help avoid or lessen this condition. This grease was actually sold for use inside the spark plug wire boot to keep the boot from sticking to the spark plug itself. I generally clean off the terminals with very fine (600 or finer) wet-or-dry sand paper and use the grease in the spark plug wire receptable that attaches after wiping as much as possibe of the rust out of the receptable. A .22 caliber cleaning brush can also be used to clean out the spark plug wire terminal that attaches to the coil pack terminal. Standard silicone grease might work, as this stuff wasn't exactly cheap. Rotating the spark plug wire boot on the coil pack terminal occasionally seems to also help this condition. I have never had a car shut down due to this condition. Not saying that it can't, though. Over all 5 cars, I have noticed that different terminals corrode on different cars. The ones that have corroded the most on my cars was the front one closest to the driver side and the 2 rear closest to the driver side? Generally the others have remained pretty clean.