Inputs For Verifiable Credentials with `proof` properties Do Not Match Data Integrity Specs

There are several JSON-LD input documents where the proof property does not adhere to the spec data model requirements of a data integrity proof outlined in https://www.w3.org/TR/vc-data-integrity/#proofs. Here's an illustrative example in example1.jsonld (which is meant to be correct)

{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://www.w3.org/2018/credentials/examples/v1"
  ],
  "id": "http://example.edu/credentials/58473",
  "type": ["VerifiableCredential", "AlumniCredential"],
  "issuer": "https://example.edu/issuers/14",
  "issuanceDate": "2010-01-01T19:23:24Z",
  "credentialSubject": {
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
    "alumniOf": "Example University"
  },
  "proof": {
    "type": "RsaSignature2018"
  }
}

But the following properties are mandated (MUST) by the spec:

verificationMethod
proofPurpose

Looking at the spec for the proof type RsaSignature2018 I can't see where/if it defines an alternative data model - https://w3c-ccg.github.io/lds-rsa2018/ and when looking at the context

This isn't the case for all of the examples, for instance example-5.jsonld has the correct construction:

{
  "@context": [
    "https://www.w3.org/2018/credentials/v1",
    "https://www.w3.org/2018/credentials/examples/v1"
  ],
  "id": "http://example.gov/credentials/3732",
  "type": ["VerifiableCredential", "UniversityDegreeCredential"],
  "issuer": "https://example.edu",
  "issuanceDate": "2017-06-18T21:19:00Z",
  "credentialSubject": {
    "id": "did:example:ebfeb1f712ebc6f1c276e12ec21",
    "degree": {
      "type": "BachelorDegree",
      "name": "Bachelor of Science in Mechanical Engineering"
    }
  },
  "proof": {
    "type": "RsaSignature2018",
    "created": "2017-06-18T21:19:10Z",
    "proofPurpose": "assertionMethod",
    "verificationMethod": "https://example.com/jdoe/keys/1",
    "jws": "eyJhbGciOiJSUzI1NiIsImI2NCI6ZmFsc2UsImNyaXQiOlsiYjY0Il19..TCYt5XsITJX1CxPCT8yAV-TVkIEq_PbChOMqsLfRoPsnsgw5WEuts01mq-pQy7UJiN5mgRxD-WUcX16dUEMGlv50aqzpqh4Qktb3rk-BuQy72IFLOqV0G_zS245-kronKb78cPN25DGlcTwLtjPAYuNzVBAh4vGHSrQyHUdBBPM"
  }
}

Could y'all point me to where the schema for this is defined that means that the values aren't required? And if they are required should we update the input documents?

w3c / vc-test-suite

Inputs For Verifiable Credentials with `proof` properties Do Not Match Data Integrity Specs #135