IIRC Anthropic models haven't all been available on day 1, so it does feel like a deliberate choice, especially since they are partners/part-owners like you say. No one would have bat an eye about some corporate PR thing "blah blah mythos is too powerful and too intelligent and so we've decided to focus our capacity on Opus 4.6/4.7/4.8 for now until we have the proper safeguards in place blah blah"