The answer depends on what you mean by "lifted". A warrant is a court order and it remains in effect until a judge quashes it or the inidividual is arrested and brought before a judge who then quashes the warrant.
If someone is in custody, in a different State than the outstanding warrant, the jailer (feds in this case) will call the agency that holds the warrant (usually a county attorney in the county of the warrant) and ask if they intend to extradite the person. If they do not intend to extradite, the individual will often be released.
My guess is that this is what happened here. Unfortunately that warrant stayed active, and the individual can be arrested at any time, lawfully, pursuant to that warrant.
The good news is that because of that warrant, he is likely to be able to apply the federal custody credit to his Minnesota sentence, and perhaps be done with probation.
If a prosecuting authority requests an interstate arrest warrant, and the subject of it is found in another state, the authorities in that other state may arrest and hold the person, then inform the prosecuting authority that the subject is in custody there. Then the prosecuting authoirty may decide to have the subject transported, or may not, in which case the person would be released. In the stated hypothetical, it sounds like the subject was never released, or at least before being released, the prosecuting jurisdiction may have changed its mind and approved transport.
A warrant can be stayed or removed and refiled at a later time when the locatin of the defendant is better known or when additional evidence is located to support a criminal charge. As a result, a warrant may issue that results in a hold when someone is set to be released from a jail facility after serving time on a different charge. The prosecuting State or Municipality would then have to determine if they wished to extradite for prosecution.
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