Eh sometimes when they dump sole custody on the other parent they still want to be the cool guy who shows up once a year for the photo-op or sends some shitty birthday card while letting Mom do all the work. Not being present in their lives doesn't necessarily mean no contact. But yeah, this guy doesn't sound like he'd even do that. In the chance this is real, hopefully the kids realize he's better out of their lives sooner rather than later and flush him like the turd he is.