Since this is not a quote, I take it as your interpretation of his belief. Do you think he still believes this today. The book is many years old, and much has changed since it was published. You say positioned, not destined. I think it is clear that China will not be dominant in the same way the U.S. has been but clearly will challenge U.S. domination.
Wisely neither you nor Ray put a timeline to your prognostications because almost certainly any dates chosen will be proven wrong.
Also consider this:
https://www.msn.com/en-us/money/markets/chase-ceo-jamie-dimon-and-billionaire-hedge-fund-founder-ray-dalio-admit-they-got-warnings-on-us-economy-wrong-for-now/ar-BB1jCDRQ
They are not all that concerned that they might be wrong. Just oh well, I got that wrong. Be careful relying on their advice.
TEK