This issue is a hot potato for politicians, none of them want to fix it. To fix it is to aconowledge the real unemployment numbers which will reflect badly on a political party.
If Political Party XYZ were in charge and changed the unemployment count to the true count, Political Party ABC will claim unemployment "skyrocketed" because of Party XYZ without the context of the count being more accurate.
And if Party ABC takes back power in this hypotherical, they would change the definition back to the inaccurate count, then claim they drastically lowered unemployment.