That's my understanding, yes. But not sure what kind of deals the larger clients can negotiate.
https://support.claude.com/en/articles/9266767-what-is-the-t...
> Team plans support up to 150 seats. If your organization is on the Team plan and needs more than 150 seats, you can upgrade to the Enterprise plan.
https://claude.com/pricing
> Enterprise: Seat price + usage at API rates
> US$20/seat/month, billed annually, 20 seat minimum. Usage cost scales with model and task.
There is no premium seat option listed for the enterprise plan