Hello, and thanks.
Man, finding out that Ho-oh was Ash's father's would be a great plot twist. It sounds great in my opinion. If they felt like they just had to leave Ash's father a secret, I guess they could always use a payphone.
FatherAsh: "Hello son."
Ash: *GASPOMG*
FatherAsh: "It's been quite a while. I've noticed your name in the news. Why don't you travel to ________, I have a surprise for you. *Hangs up*
Ash: "Wait, what?"
Ash would then travel to ________. Maybe he'd see an evil gang trying to gain control of Ho-oh and some other legends.