Looks like most of the other subtests from https://searchfox.org/mozilla-central/source/testing/web-platform/meta/html/cross-origin-embedder-policy/reporting-subresource-corp.https.html.ini have expectations set for beta, made a patch if we're going the same way with the newly added subtest.
Bug 1661699 Comment 3 Edit History
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Looks like most of the other subtests from https://searchfox.org/mozilla-central/source/testing/web-platform/meta/html/cross-origin-embedder-policy/reporting-subresource-corp.https.html.ini have expectations set for beta or release, made a patch if we're going the same way with the newly added subtest.