To quickly lower expectations before reading the article:

> Every year with these Arm flagship chip announcements, the company also includes a wild design for a giant mega-chip that usually never gets built.

That being said, this 14-core figure is when doing a full-Arm SoC (with Arm internal bus). SoC vendors are still allowed (AFAIK [0]) to do their custom interconnect that goes higher than that

[0] there have been rumors seen here that Arm is pushing towards a model where SoC vendors must do all-Arm components. That still sounds weird to me, and I'm not witnessing any actual effect of this, so I still highly doubt it.