Why SPM propagate platform requirements when using macros?

I've come across a problem when using macros in my app, which has a minimum deployment requirement of iOS 12.

I noticed it is not possible to do so because the minimum version of which SwiftSyntax supports macros is 509.0.0, and in its Package.swift it clearly states .iOS(.v13).

My question is, since macro implementations are executed in a sandbox and never affect runtime behavior of the host app, when I specify the dependency of SwiftSyntax in my macro implementation package via

.macro(
  name: "MyMacros",
  dependencies: [ ... SwyftSyntax... ])

, is it possible for SMP not to propagate its platform requirement to the host app in a future release?