In other words, "did you make up that thing you just wrote?" As it turns out, no, I did not. But I'm delighted you would imply that I did! At times my faith in online discourse gets a little too high, and it's healthy to recalibrate.
One example of what I was talking about (merely the first I was able to quickly google): the requirement for Fulbright scholars, who are paid to study at the graduate level in the United States, to return to their home countries, at least for a time, before trying to come back to the US:
You and your dependents are subject to Code of Federal Regulations rule 212(e), the two-year, home-country residence requirement associated with the J-visa. As noted throughout this guide, the spirit of the Fulbright Program is to increase mutual understanding between the people of the United States and the people of other countries by means of educational and cultural exchange. When you have completed your grant, you are expected to return home to share the knowledge you have gained. This means that until you have resided and been physically present in your home country for a combined total of two years following your departure from the United States, you and your dependents are ineligible to apply for status in the United States as:
Permanent residents,
Temporary workers or trainees (visa status H)
Fiancé(e)s (visa status K)
Intracompany transferees (visa status L)
Grounds for applying for a waiver of the two-year, home country residence requirement are extremely limited, and approval of waiver requests is rare. IIE cannot assist in this process. Waivers should not be requested as a means of continuing your grant activities.