This is incorrect. IF induces ketosis. Ketosis burns stored fat. Caloric reduction is insufficient to induce ketosis and therefore is insufficient to burn large amounts of fat stores.

Excess calories simple carbs get stored as fat. Fat burning kicks into high gear under ketosis. Therefore, you can get major weight loss acceleration from anything that induces ketosis and doesn't result in an equivalent amount of simple carb storage.

Under an IF regime, if you ate the same amount as you eat normally, which many IF people do, you will burn fat faster and therefore lose weight faster. Many who do IF eat there 3 meals within an 8 hour window and do not constrain calories.

The duration of ketosis will be the deciding factor if you're not over-consuming carbs. If you fast for 1 day out of 7 you will burn far less fat then if you fast for 16 out of every 24 hours.