That article is using a nascar engine. High compression race motors held as constant high RPM tend to have different issues to a street mx5 so I wouldn't give it a great deal of thought. Personally I'd get my headers coated if I was going to have the headers/car for a a long time. I always planned on going turbo so I ran heat wrap which ended up being for 6 years on my racing beat headers... previous owner I bought the headers from had the same headers wrapped years as well. I never had any leaks or blown gaskets during that whole time I ran them. There were some cracks in the header when I sold them last year which had to be welded before the next owner could ceramic coated them but those headers saw race use in 2 cars over 10 years and I had no transmission exhaust mount so they had a decent weight twisting them on a LONG lever for nigh on 10 years
The real considerations for you will be how long you want it to last? I re-wrapped headers 3 times in 6 years... it slowly falls apart between moisture and heat cycles. Most of the stuff has glass fiber as well which bites into your hands. You'll want some decent gloves and probably some clothing you won't mind throwing out... It's way easier to do it off the car.
Just realized I overlooked you staid stock headers, I wouldn't wrap those. The wrap would hold moisture on the header and that should accelerate corrosion ....