Really??? In 99% of cases, the only thing that airline ticket/gate agents every checked in my passport was the Visa, which was a U visa. Only once or twice have I been asked if I had an OCI booklet by an airline agent. I just returned from a trip to the subcontinent this week, and even at Immigration in DEL, the U visa was examined, and the entry and exit stamps were on the opposite page.

Of course, I can't see why the Indian authorities would require two separate documents testifying to the same thing (the card and the visa stamp). However, the U visa no longer a requirement? This is the first I've heard of it.