Yale scholar Jim Wood notes that preserving the subject-verb inversion in embedded questions is becoming a grammatical feature of several dialects of English, especially Irish:
Rita Hanratty stepped forward to greet him. With a sort of shyness, he asked could he have a cup of tea. — Drogheda Independent website, dateline: 21 Oct. 2017.
Without if or whether or intervening comma, this is a fairly recent innovation in reported speech that preserves the inversion of the original, only changing the pronoun.
This preservation is also a new feature in unreheared spoken American English, and occasionally in written sources as well.
Headline: The Left wants to know where is leadership when Price, others are accused of misusing taxpayer money — Atlanta Constitution website, dateline: 29 Sept. 2017.
Now I imagine that the imbedded question here isn't imbedded at all, but only appears so in print because the headline writer wanted to save the space that would otherwise be wasted on a comma, two double quotes, and a question mark. It does, however, give the reason why a construction preserving the inversion could arise. Here, there is not even a pronoun to change.
Querying the Corpus of Contemporary American English (COCA) for the string what is a good shows that this construction, though not yet common, is current across the Atlantic:
Obviously, they [teachers at a Jesuit school] imparted to you your religious faith, and from that, I think, political and [sic] ideas about what is a good society. — NPR Weekend, 4 Jan. 1992. COCA
We can’t take away the judgment of individual financial institutions about what is a good credit risk. — National Review 45(1993), 25, 52–54. COCA
…the questions of what is a good nursing home and when a caring household is no longer a home. — Health and Social Work 19(1994), 3, 174–87.
This is an interesting example in that it preserves the inversion of the first question but not the second. It is impossible to tell whether the word question triggered the first as a direct question with no punctuation or whether the writer uses the construction with what but not when.
Well, tell us how you come to decide what is a good toy, what really means something. — CNN News, 26 Nov. 1995. COCA
… the judge who has not understood what is a good photograph… — PSA Journal 61(1995), 8, 9. COCA
Honestly, how can they say what is a good match for me and what is a good match for him? Ebony 59(2000), 6, 149. COCA
Well, he is doing some sort of testing to see what is a good team effort here. FOX _On the Record with Greta Van Susteren, 5 July 2012. COHA
I'm looking for the criteria of what is a good investment and a good idea. — CNN Newsroom, 26 July 2015. COCA
To comfort those who find this construction disconcerting, I also queried COCA for the collation what a good and is within four following words and got 36 hits that reverse the inversion as traditional English grammar requires.
Ambiguity and the Two Whats
Also instructive were two results from the prior query that illustrate why the distinction between interrogative what functioning as a relative pronoun and what as a garden variety relative pronoun in which inversion is never an issue can be obscured:
So therefore, pretty much to you what is a good chocolate is what makes you smile, what you like. — NPR Talk to the Nation 16 Dec. 2003. COCA
Is this the embedded question, “To you, what is a good chocolate?” Answer: what makes you smile. Or is it something like:
What to you is a good chocolate is a dark, bitter slab of brittle fat to me.
I think this is what this speaker had in mind rather than using a new way of imbedding questions.
Another example comes from former President George W. Bush as he discussed Obama’s strategy against ISIS:
And the President has laid out what is a good goal, and that is to degrade and defeat ISIS. — CNN State of the Union, 7 Dec. 2014. COCA
This too is not an embedded question, but Bush speaking about a goal that’s good, namely…
The point here is that what as a relative pronoun alone sets up a pattern that can run counter to what as an imbedded interrogative requires in standard English, and that the word order of the former might be influencing some native speakers to follow that pattern in the latter. Only time will tell whether the preservation of inversion in imbedded questions will be accepted as standard.