It is a moot issue, it expired over 30 years ago.
From Wikipedia:The original joint resolution (H.J.Res. 208), by which the 92nd Congress proposed the amendment to the states, was prefaced by the following resolving clause:
Resolved by the Senate and House of Representatives of the United States of America in Congress assembled (two-thirds of each House concurring therein), That the following article is proposed as an amendment to the Constitution of the United States, which shall be valid to all intents and purposes as part of the Constitution when ratified by the legislatures of three-fourths of the several States within seven years from the date of its submission by the Congress:
As the joint resolution was passed on March 22, 1972, this effectively set March 22, 1979 as the deadline for the amendment to be ratified by the requisite number of states. However, the 92nd Congress did not incorporate any time limit into the body of the actual text of the proposed amendment, as had been done with a number of other proposed amendments.
It doesn't matter. It was clearly the intent of Congress to have a deadline.