The Law of Return gives every Jew the right to immigrate to Israel.
The Citizenship Law was amended in 1971 to allow any Jew who formally expresses their desire to migrate to Israel to immediately become an Israeli citizen, without any requirement to enter Israeli territory. This change was made to facilitate emigration of Jews from the Soviet Union, who were routinely denied exit visas, especially after the 1967 Six-Day War.
In other words, the change was to facilitate imprisoned Jews moving to Israel. Has no bearing on American Jews.