Anchor will not make backwards-incompatible changes such as removing a field from the API without reaching out to you first. We're continually making backwards-compatible changes to the API. Examples of things we do not consider "breaking" include:

Adding new optional request parameters to existing API methods.
Adding new properties to existing API responses.
Changing the order of properties in existing API responses.
Adding new API resources or methods.
Changing the length or format of opaque strings, such as resource IDs, error messages, and other human-readable strings.