You know India is on the 60 days visa exempt list. The new regulations are effective from mid july. Many hunderd tousand tourist got this stamp already. Its not even news anymore. So why ask?
I guess its a officer who not accepts a empty datefield. Same as they always make me add a departure date if i request a re-entry permit. Make up any date and its fine.
You can most of the time get a new slip. Your initial TM30 is in the system and your adress did not change. I always make a copy from the slip or at least a picture.