[Blablabla]

He said Woli was to be his last son... and after reading what they said to each other in 892, it just means that :

Spoiler:

Woli is going to learn more about boxing and improve. So yeah, maybe he will cross an other time Ippo's path to Martinez's moustache.

Or, Woli won't be able to "recover" from that fight and his boxing career will end. I'm more up to physical sequels ala Ryuhei or even worse than a mental breakdown. Woli wasn't afraid by Ippo's power even he realized that he won't be able to move and dodge anymore.