Yes, it is true.
However, in the case you present, the couple are, in fact, both considered U.S. Residents for tax purposes. By filing a joint tax return with a citizen spouse, the non-resident alien has elected to be treated as a citizen/resident alien for tax purposes, so this particular statute does not apply in this case.
The choice can be revoked as follows:
Ending the Choice
Once made, the choice to be treated as a resident applies to all later years unless ended in one of the following ways.
If the choice is ended in one of the following ways, neither spouse can make this choice in any later tax year.
Revocation. Either spouse can revoke the choice for any tax year, provided he or she makes the revocation by the due date for filing the tax return for that tax year. The spouse who revokes the choice must attach a signed statement declaring that the choice is being revoked. The statement must include the name, address, and identification number of each spouse. (If one spouse dies, include the name and address of the person who is revoking the choice for the deceased spouse.) The statement also must include a list of any states, foreign countries, and possessions that have community property laws in which either spouse is domiciled or where real property is located from which either spouse receives income. File the statement as follows.
If the spouse revoking the choice must file a return, attach the statement to the return for the first year the revocation applies.
If the spouse revoking the choice does not have to file a return, but does file a return (for example, to obtain a refund), attach the statement to the return.
If the spouse revoking the choice does not have to file a return and does not file a claim for refund, send the statement to the Internal Revenue Service Center where you filed the last joint return.
Death. The death of either spouse ends the choice, beginning with the first tax year following the year the spouse died. However, if the surviving spouse is a U.S. citizen or resident and is entitled to the joint tax rates as a surviving spouse, the choice will not end until the close of the last year for which these joint rates may be used. If both spouses die in the same tax year, the choice ends on the first day after the close of the tax year in which the spouses died.
Legal separation. A legal separation under a decree of divorce or separate maintenance ends the choice as of the beginning of the tax year in which the legal separation occurs.
Inadequate records. The Internal Revenue Service can end the choice for any tax year that either spouse has failed to keep adequate books, records, and other information necessary to determine the correct income tax liability, or to provide adequate access to those records.
Snipes