For East Asia, 1550 is just a weeeee bit early to say for sure, unfortunately. In the Phillipines and Spice Islands (Modern Indonesia), Portuguese and Spanish traders had plied the spice trade for a half century, and Magellan's 1521 voyage had proven that the Phillipines could be reached by sailing around the New World. That is to say, in South East Asia, some of the locals probably were aware of the New World by 1550. I can't speak to how many, or who. East Asia was a different story. Certainly by 1552 the Portuguese had established themselves in Macao, and after that date we can say with some degree of confidence that certain people in southern China probably knew about the New World. Let's remember, however, that from the mid 15th century onwards, the Ming leadership more or less maintained an isolationist policy. Zheng He's voyages were the last major Chinese exploratory expeditions. I'm not sure how interesting the Ming dynasty would have found information about the Americas specifically.

Japan and Korea were a different story. I know that the portuguese made contact with Japan as early as 1543, but I can't speak to the frequency of trade missions there. I vaguely recall something about the Dutch helping the Japanese build a Western style ship which then sailed to Acapulco, Mexico and conducted direct trade across the pacific that way. Some one else will have to fill you in on the details there.

Korea under Joseon was extremely poor, and probably not of great interest to European traders. I can't recall any specific interactions between Korea and Europe before the 1580s. However, there were Portuguese mercenaries on both sides during the Imjin Wars (1592-1597).

tl;dr: in 1550 probably not, but circa 1552 probably yes.

If I'm not mistaken, the Kunyu Wanguo Quantu from 1602—created by the Jesuit Matteo Ricci and two Chinese collaborators—revealed the existence of the Americas to the Chinese, and quickly reached Japan as well.

As an interesting side note, however— not even all Europeans would have been aware of the existence of the Americas until around this point. Even though Columbus' first letter had been published in 1493, along with other works in the decades immediately afterwards, they were still eclipsed by sales of earlier, more fantastical travel accounts like those of John Mandeville. Things started to change when more popular works on the subject, like Peter Martyr's De Orbe Novo (1530) and Sebastian Münster's Cosmographia Universalis (1544), were published and read. [Source: Lucien Febvre and Henri Martin, The Coming of the Book]

Jesuit missionaries showed Oda Nobunaga (1534-1582) a globe and explained to him that the world was round. This is a pretty famous story since Nobunaga was the only person to understand it among the Japanese listening. Also in 1581 Nobunaga bought an African slave from the Jesuits, freed him and made him a samurai retainer. His name is Yasuke, he was originally from Mozambique.

So some Japanese clearly knew that the globe was round and that there were the Americas, Europe, and Africa by 1582.