When SKULabs detects inventory was pushed for an FBM SKU which has converted to an FBA offer, it provides a one-time option to overwrite your prior FBM inventory with 0 stock just in case Amazon mistakenly reactivates the original offer during a batch update or perhaps when your listing publishing / PIM updates the product.
Why is this needed?
SKULabs has built-in protections and won't push inventory to FBA listings. Use this feature to troubleshoot/override issues with Amazon reactivating your listings as merchant-fulfilled with incorrect inventory. Use of this feature can curb or prevent overselling.