"The IRS will then adjust returns for those married filing jointly taxpayers who are eligible for the up to $20,400 exclusion and others with more complex returns."

You notice they don't say when this will start (or end). Do you think they'll do those "complex" returns any faster if a 1040-X is filed?

And nothing about whether interest will be paid on the refunds -- as it would be, if amended returns are filed.