>The bank's analysts then assumed Anthropic gross profit margins of 60%, and estimated that 75% of related costs are spent on AWS cloud services.
Not estimate, assumption.
If Morgan Stanley are willing to stake their credibility on an assumption I'm going to take that assumption seriously.
Those are estimates. Notice they didn’t assume 0% or a million %. They chose numbers that are a plausible approximation of the true unknown values, also known as an estimate.