I don't know what "high on the list" means, exactly. But the Knicks are interested in making the move nonetheless.
The issue for New York, of course, is that Lawrence Frank is still under contract and they'd need the Celtics' permission to talk to him. And there is no way the Celtics will give the Knicks permission to talk to Frank to essentially have him make a lateral move.
It's one thing for the C's to let Lawrence go all over creation to try to become a head coach. Doc has said he'd never stand in someone's way if they're in line for a head coaching job. But to let the guy in charge of your defense go to a division rival to do the exact same job (and pass along whatever state secrets that might involve) would be insanity.
Still, this is the New York Knicks. These are the guys who are letting Isiah Thomas come back and pull strings after he embarrassed the franchise and hamstrung them for years. They might not know the rules… or they might be too arrogant to think the rules apply to them.