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TH200 that was only installed in small engine vehicles in the 70s. It was prone to failure in anything with a larger engine (5.7L and higher was called out in the article).
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This is correct, the THM200 was originally designed for the 1.6 L chevette application. When installed in anything with a V8, 301 P, 5.7 olds diesel (110 HP), 305 chevy, plus numerous 3.8 buick applications, it was extremely undependable. It had some improvements for V6 and V8 applications, however was still inadequate for stock applications.
I had an 81 Bonneville diesel, and a 78 301 GP with THM200, that expired in under 70,000 miles with no abuse, plus many customer cars that had premature transmission failures.
The 200 4R was also steadily improved as GM did their field testing, especially in the late 70s early 80s used in the field testing with customers being the test subjects. One of the key reasons GM lost much of their market share.
One other thing is the full electronic controlled transmissions can be adjusted without raising the hood, or crawling under the car, just adjust the TCM from inside the car.
The OPs thoughts of using a transmission that was originally designed for tough usage, in heavy vehicles, with engines that were not anemic in stock form, is probably going to be the best path to reliability over the long haul.
Most any T400 or 4L80E in stock form will withstand the engines power of 90% of the street cars on PY. Going from the stock 440 ft lb torque rating of either transmission to almost doubling it to 750 ft lb is pretty easily accomplished without replacing every hard part inside of the case.