Because they didn't read any of the sources and just heard about the NYPD requirement that they call the tip line, which they didn't do, so unless there's some major backlash, they definitely won't be getting $10,000 of the reward.
The other $50,000 from the FBI we're all kinda assuming will have some other reason to not be paid out, but if we're being honest, if the 1% want us to continue turning on each other in the future, they're gonna have to let these high profile snitching cases go through.
https://kpel965.com/mcdonalds-employee-may-not-get-60000-reward-for-tipping-off-police-about-luigi-mangione/
This one was posted further up. The tl;dr is that because they didn't call the NYPD tip line, they definitely* won't get the $10,000 from them, barring major backlash that may make them walk that back.
The $50,000 from the FBI is up in the air, but is dependent on him getting convicted. There's some wording that someone else pointed to about the tip needing to lead to an arrest AND conviction, saying that because the tip itself only lead to the arrest, they won't be paid, but I'm uncertain about that.
I mentioned in another comment that if the 1% want us to keep snitching, these high profile situations kinda need to pay out.