Upgrading hardware is an ongoing process. You are proposing a single point of change without any reason for it to be handled that way.

You are arguing that all change has the same cost. I don't see your reasoning for this. A smaller change to a system has a lower cost in R&D, and a lower cost in manufacture.

Although it is probably true that the cost of updating all equipment dominates the cost of redesign, this is only an issue for a big bang update rather than a rolling upgrade.