I heard about this from someone before being directed here.
POTENTIAL SPOILERS BELOW
As always it's good to take this rumor with a grain of salt at the moment. Unless it's confirmed I really have no feelings on this. Although the phrasing is weird as the person claimed they were "killing another Robin" in the quote. I think the implication is them asking if it was Tim before that but anyway let's assume it's true.
That would mean all four of Batmans' Robins died. Plus Bruce too with the Endgame stuff but from a mentor stand point that's 100% failure.
Dick Grayson: This one gets the most leeway as Lex Luthor only "killed" him for a very short time. I think it gets far too blown out of the water on Dick being dead like when that was part of the ad for Grayson. But DC seems to count it so it's here.
Jason Todd: The first and most famous death. When everyone thinks of Batman losing his sidekick or a dead Robin this is the one that comes to mind. He's also been the one to remain dead the longest.
Damian Wayne: Honestly I thought this death was over done and over hyped. There's no way you can compare it to Jasons' long absence and the stories that came from that.
Basically the idea of killing Tim feels like another attempt to make a cheap repeat of Death in the Family. Doing so makes Batman look really bad, once again reduces the impact of Jasons' death/rebirth and takes away the normal kid vibe from the Robins. Also? I do not believe for a moment it's going to stick with so many creators loving Tim Drake. It makes this feel like a desperate attempt to make him relevant by copying another story.
I love my Robins and I think Tim deserves better. I think they all deserve better and if this story is true it feels pointless. The only thing that would make me cringe more than the concept is how he would die.