Father cuts children out from first marriage. Common?

Hello All,

USA - NH

Father has a few kids from marriage #1.

Divorced , then moves on to marriage #2 and has more kids.

How common is it for father to do nothing that will ensure kids from marriage #1 get something?

Fyi - kids from both marriages don't really know each other.

Other that father telling #2 kids how bad #1 ex wife and his kids from that marriage suck.

Most assets are joint with father and wife #2.

Just curious.

Thanks in advance