It is pretty diffcult to find and show cause and effect in these circles, but I wonder about this interpretation a bit. Popular music can be accessed everywhere in the world these days even though I would think linguistic and even geographical preferences kind of apply.
Also, Jeremy had been skating pro for years when he used In This Shirt, had he not? Both of them used the song in Stars on Ice which is a biggish show and even gets televised, but just how much the shows inform choices of music in competetive circles, I don't know. I doubt that their influence would be huge, although YT does provide some access to these shows (both performances can be found there). Music used in show contexts does not necessarily get viewed as suitable for competitive programs - I remember reading that Nathan Chen felt Nemesis was felt more like a show song, but still decided to give it a go.
Moreover, I don't think either of these older guys particularly progressive in their choices of popular music (more so in modern or classical music), particularly in their pro careers - pretty standard middle of the road stuff when you look at the list. But in both cases of In This Shirt, there is the factor of choreographer. Jeffrey's version was choreographed by Linda Garneau, a dancer and choreographer from outside the FS world. In Jeremy's case there is a Team France connection, Benoit Richaud. It is not possible to show who came up with the song, but here I would almost go for outside influence.
Unlike Jeffrey and Jeremy, Kevin has a pretty strong track record for choosing somewhat alternative pop music for his programs - Imagine Dragons, Benjamin Clementine, Woodkid all before In This Shirt. He could very well have listened to The Irrepressibles long before choosing to skate it.
This would not be the first time Team France would have come up with sth different - Benjamin Clementine (with a strong French connection) was used by Florent Amodio and then Kevin after which Shae-Lynn picked it up for Nathan Chen. Woodkid (who is French btw) appears in a free dance by the then virtually unknown Papadakis/Cizeron in 2013-4 and was picked up Simon Hocquaux, a French skater for his last junior SP in 2014-5. And then a bit later by Kevin and then Nathan Chen. Once an unusual piece of music has a proven good track record in competition, it tends to get repeated.
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