Mind sharing the source of it, where it is written?
There is nothing like it, in fact it is being said by the workers at Total pumps, oil change stores, etc. that 9000 means for 9000 Kms, 5000 means for 5000 Kms, etc.
Do not fall prey to such marketing gimmicks or tactics!
Some companies even claim that their some oils last 15-25,000 Kms drain intervals, where as in their products data sheets, they have clearly mentioned to follow the recommended drain interval mentioned in the owners / users manual, i.e. "Jaagday raina, saaday tey na raina..."
Then why the gimmick of 15-25,000 Kms drain intervals, when manual is saying to replace after 5000 Kms, along with genuine oil filter?