I don't see anything on that page directly supporting that. The closest is this:

In most countries, the number of placements for students in medical schools and clinical internships is limited, typically according to the number of teachers and other resources, including the amount of funding provided by governments.[1] In many countries that do not charge tuition payments to prospective physicians, public funding is the only significant limitation on the number of physicians trained. In the United States, the American Medical Association says that federal funding is the most important limitation in the supply of physicians.

And this bit of the AAMC saying we need more:

In the US alone, the Association of American Medical Colleges (AAMC) estimates a shortage of 91,500 physicians by 2020 and up to 130,600 by the year 2025. However, a bias would clearly exist in their estimates as expanding medical education serves the direct financial needs of the AAMC.[52] As previously mentioned, the World Health Organization (WHO) estimates a shortage of 4.3 million physicians, nurses and other health workers worldwide.[3] The WHO produced a list of countries with a “Human Resources for Health crisis”. In these countries, there are only 1.13 doctors for every 1,000 people. In the United States, there are approximately 2.5 doctors for every 1,000 people.[53] One quarter of physicians practicing in the United States are from foreign countries. Thousands of foreign doctors come to practice in the United States each year[54] while only a few hundred doctors from the United States leave to practice in foreign countries even short-term.[55]