You're missing the point. The root of this discussion shouldn't be about the cross-compatibility of EternalBlue between different architectures. I'm not, hospitals aren't, nobody here is talking about this. You're right in saying that there's a fuckton of embedded systems that wouldn't be vulnerable, but those systems are not relevant, because they wouldn't have been affected.

And no, doctors aren't going to need to transfer their valuable sensitive data via physical medium in a airgap. A optimal solution to dimish this possible threat is creating an airgapped network for life-critical systems.

Financial systems, military equipment, air traffic, many valuable sensitive and critical systems are airgapped. The only simplistic and realistic way of compromising an airgap is via physical access, in which, your security is already compromised.

Explain to me, how every modern military has their most critical networks setup? Or financial systems? Maybe I'm wrong and I'm misunderstanding what you propose but it seems like by your explanation your definition of airgap and mine are different.