org.keycloak.provider.*  from keycloak-model-api  is used by most of the modules which implement certain Spi.

A module (X) having keycloak-model-api (Y) added as a dependency may in turn be used by classes or other Spi's in keycloak-model-api (Y) and thus result into a cyclic dependency.

X dependent on Y for org.keycloak.provider.* classes

Y dependent on X for X specific services/SPI's or classes

keycloak-core is used by many modules but in turn keycloak-core doesn't uses any of keycloak-* dependency and hence will not result into any issues like cyclic dependency. So, may be moving org.keycloak.provider.* from keycloak-model-api to some other(like keycloak-core) will be helpful or may be a better practice.

If this seems fine, I will be happy to make the required changes :)

Cheers,