> Some people have pointed to similarities between the incidents, with some experts citing satellite data and evidence from the crash scene as showing links between Sunday's disaster and October's crash in Indonesia of the Lion Air jet that killed 189 people
The USA and Canada banned flights after those similarities were discovered, so my guess is that they are more than just passing similarities. E.g. it could be something like the two planes crashed at exactly the same times into their journeys.
I think it would be debatable that a safety risk was known after the first crash. But after the similarities between the two crashes came to light, it was definitely time to stop and they did.