A change in the minor component signifies a non-breaking change, and that the consumer can safely use the new version without breaking, although the consumer might need to be updated to use its new functionality. For example, adding a non-mandatory feature column with a default value to the model is a minor bump, because when a value for the added column is not passed, inference still works.

Using semantic versioning facilitates model deployment, by communicating which if a new version can be deployed without changes to the application:

My understanding is that the caret is the answer for traditional SemVer, i.e., there will be breaking changes prior to 0.1.0, there may be breaking changes between minor versions prior to 1.0.0, and there may only be breaking changes between major versions above 1.0.0.

The TypeScript team has made it clear. They do not follow semver. "minor" (X.X) releases can contain breaking changes. Major releases (X) have very little meaning.

For better or worse, TS doesn't do semantic versioning; see #31761

Unless we choose to use the semver ju-jitsu of calling the changes a bugfix

The versions must be compatible, so if a peerDependency is listed as 2.x, you can’t install 1.x or another version. It all follows semantic versioning.