There is not one article out there out of hundreds that suggest flaring elbows out during a close grip bench press is a proper way to train triceps.
When putting your elbows in an unnatural position, you are taking the stress of the triceps and placing immense stress on the elbows, shoulders, and chest.
Years ago, Tom Prince a pro-bodybuilder injured his elbow from this abusive flaring technique.
There are many more articles out there, but they are in health and sport science journals and not on the web.
I would never ever teach anyone to flare their elbows when using the close grip bench press.
Powerlifters are also agains flaring elbows because it results in injury and places negative stress on the delts and rotators.