Unless they have actually done that, the claim is bullshit. Any state that does do it is just diluting its influence on the national election. It's not in the best interests of any state to do it. Therefore, it will never happen.
The movement for a national popular vote is based on states agreeing to allocate their electoral votes to the national popular vote winner
once a majority (in the Electoral College) of states have agreed to do the same. That is, their laws don't take effect until enough other states have passed similar laws. At which point the national popular vote winner is guaranteed to receive 270 electoral votes and assume the presidency.
They're up to 132 electoral votes cumulative at present.