Coronavirus: Lab Leak Part 8: arguments for and against the importance of the CGG-CGG combo?

Will CGG-CGG be for 2021 what COVID-19 was for 2020? 

The Wall Street Journal (Jun 6) had the following to add to the lab leak hypothesis and the importance of the CGG-CGG combo:

If the insertion takes place naturally, say through recombination, then one of those 35 other sequences is far more likely to appear; CGG is rarely used in the class of coronaviruses that can recombine with CoV-2.

. . . In fact, in the entire class of coronaviruses that includes CoV-2, the CGG-CGG combination has never been found naturally. That means the common method of viruses picking up new skills, called recombination, cannot operate here. A virus simply cannot pick up a sequence from another virus if that sequence isn’t present in any other virus.

Although the double CGG is suppressed naturally, the opposite is true in laboratory work. The insertion sequence of choice is the double CGG. That’s because it is readily available and convenient, and scientists have a great deal of experience inserting it. An additional advantage of the double CGG sequence compared with the other 35 possible choices: It creates a useful beacon that permits the scientists to track the insertion in the laboratory.

Dr. Amy Maxmen on Twitter countered with:

Andersen also pointed out that feline coronaviruses have CGG-CGA, meaning it's a single nucleotide difference (ie evolution can make these codons in viruses). An A to G switch happens frequently because it's synonymous, it doesn't change the function of the amino acid. pic.twitter.com/phlmPXAoeO

— Amy Maxmen, PhD (@amymaxmen) June 7, 2021

I'm not a scientist, but reading the WSJ and the Tweets, it seems to me that they agree on the fact that CGG is rare. The WSJ states "CGG is rarely used in the class of coronaviruses that can recombine with CoV-2." The first of the above tweets from Dr. Amy Maxmen states, "CGG is rare in coronaviruses but it exists." Okay, they appear to agree on this. I think the issue is the CGG-CGG combination. The WSJ states, "the CGG-CGG combination has never been found naturally." Dr. Amy Maxmen states, "Andersen also pointed out that feline coronaviruses have CGG-CGA, meaning it's a single nucleotide difference (ie evolution can make these codons in viruses). An A to G switch happens frequently . . . "

It seems to me that the WSJ has the stronger hand here. They state that the CGG-CGG is used specifically for research. "Although the double CGG is suppressed naturally, the opposite is true in laboratory work." Amy Maxmen is left with saying that a switch from A to G could have happened. 

Does the above prove or disprove the lab leak hypothesis? I don't think so, but it does lead me to believe that both are valid possibilities.