no idea why you keep repeating this kind of infomation here. 12ga should be fine for a bicycle, just dont use some low budget rim.
I've built and serviced thousands of wheels, including pedicab wheels that carry 700 lbs or more
per wheel. I've ridden daily for decades at body weights up to and exceeding 400 pounds.
Yes, you can use 12ga or 13 gauge spokes. But the resulting wheel will become a problem
at a lower static and dynamic load than if you use 14ga, or better 14-15ga double butted spokes.
The e-bike I rode today has a wheel from an early Rad Wagon, with the crowd-pleasing but incorrect 12 gauge spokes. I had already tightened the spokes until my thumbs complained when I first installed this wheel a few months ago. Ever since, the stupid fat spokes rub together and creak when the wheel turns under my now 250-something pound weight. So today at work, I turned the tension up another notch even though it was taking my hands and the spoke nipples to their limits of endurance. It still friggin creaks. Idiots.
The wheels I have with the most accumulated miles, no broken spokes, no problems in almost 24 years, have 15-16ga spokes (1.8-1.6mm double butted). They're laced to drum brake hubs and 48 hole tandem rims.
The pedicab wheels I designed and spec'ed use 14-15ga spokes (2.0mm-1.8mm double butted). They came to market at about the same time that Coaster Pedicabs and Main Street Pedicabs introduced their own "premium" wheels with 12ga spokes to serve requests from ignorant people. Those were nothing but trouble and were promptly discontinued. Meanwhile a lot of the many hundreds of thin spoked wheels I built are soldiering on.
The thinner the spokes, the more you can load and therefore flex the rim before they go slack. When they go slack, you get problems. So enjoy your problems, but I'm not going to shut up about how you're wrong.