The timing of this is what seems fishy to me. As the article says, they banned a competing payments app just before one of its features would've benefited from the Indian Premier League (popular cricket competition in India).
I'm all for setting high bars (or even preventing) anything gambling-related, but this could've been done a lot earlier and with sufficient public warning. Regular people, especially those who use Paytm for day-to-day stuff and aren't tech-savvy enough to switch to something else quickly are going to be hurt from this. This reeks of high-handedness at best and active sabotaging of competition at worst.