Luther thought Sacraments were heresy, images (icons) were idolatry, and the only authority was Scripture. Don't think he would've fit in well with the Orthodox.
Beside that point, Eastern Orthodoxy was extremely foreign to western Europe outside of Venice. (The Latin Crusaders didn't have a very high opinion of the Byzantines either.) May as well ask why he didn't convert to Confucianism.
What do you mean, "sacraments were heresy"? As far as the Eucharist was concerned, he was very
strongly opposed to anyone who would downgrade the significance of the Eucharist, to the point that he labeled Zwingli's followers as being of the devil. He said "I would rather drink blood with the Papists than wine with the Zwinglians" meaning that on the issue of the Eucharist at least, he still sided with Rome against Zwingli. His views on Baptism were similar to Augustine's, too (he affirmed baptismal regeneration, unlike Calvin and Zwingli).
He did, however, deny that Confession/Absolution, Chrismation, Anointing of the Sick, etc., were sacraments. He insisted there were only two of them. Even though the Lutheran church did continue to practice auricular confession, they denied it was a sacrament. That is
a major departure from Orthodoxy, which affirms that there are more sacraments than just two (without necessarily endorsing the RC claim that there are exactly seven).
Luther also preached against iconoclasm and denounced the Zwinglians for engaging in it. He opposed venerating
images, but not the use of images themselves (he thought they should primarily be used for didactic purposes). Unlike Calvin, he didn't go whole-hog on rejecting everything the 7th council taught, although he certainly had mixed feelings about some of its teachings.