The refinance is a real issue, but it doesn't matter too much cause the Fed can (and will) always intervene. They can soak up any supply to push the 10 year down.
Same reason why it doesn't matter if China etc.. wants our treasuries. Fed is always there to buy them.
I'm not an economist but I believe this is only the case so long as USD is the global reserve currency. If that ceases to be the case, the Fed has a lot less power to print money and inflate debt away. I believe this is the case Ray Dalio has been making for some time now:
Same reason why it doesn't matter if China etc.. wants our treasuries. Fed is always there to buy them.