Yes, I took a look at this article you gave a link to here.
Honestly, half way through the first paragraph, mainly when I reached this sentence -
"However, you can increase the energy efficiency of your home by asking your electrician to use a larger gauge wire than the minimum recommended size."
I realized this was not written by someone who really knows what they are talking about. Seems more to me that this person took clips of what they read on the Internet elsewhere and put it together in their own way.
"If you have an outlet in your home wired with 15 amp wire, and you plug in a 20-amp appliance, you’re asking your wiring to deliver more current than its capacity rating."
I can't think of any time that I saw a 20-amp rated appliance used in a home other than maybe an a high capacity "UPS". If you take five 6-amp appliances and plug them in and run them all at the same time on one 20amp circuit you are still going to trip the breaker.
Persons with formal education in electrical theory and being trained in the trade of "Electrician" will look at this article and can pick it apart.
Wiring your home - other than where required to have a 20amp circuit such as a SAC, laundry circuit etc you can run all 15amp circuits (14 gauge) and you can put 25 receptacles on the one circuit or you can put only one receptacle on the circuit. The number of receptacles are meaningless when not being used.
Having a 20amp circuit with 12 gauge wire - run a vacuum cleaner and hair blow dryer on the same circuit at the same time and dimes to donuts you will trip the breaker.