One interesting aspect of this issue that the article doesn't mention (actually the article skims over a lot of stuff): this whole "engine inlet overheating" is

One interesting aspect of this issue that the article doesn't mention (actually the article skims over a lot of stuff): this whole "engine inlet overheating" issue wouldn't be a problem for other airliners, because newer designs have an AUTO setting that makes sure that the heating is turned on when it's needed and turned off well before it can lead to overheating. But the Boeing 737 can't have such a setting because it never had one, and Boeing is very intent to change as little as possible, because making too many changes might lead to the FAA deciding that the MAX needs a new type certificate (or at least extensive retraining for pilots trained to fly previous 737 generations).