There are US casinos that use them... Look at the Jacks Detroit set... Even the old MGM set had 43mm Baccarat chips that were taken out of play after two days (never heard definitively why).
I don't think you'll see them replace 39mm anytime soon. Doing so would require replacing and the dealer trays, chip racks, etc. Some casinos don't give much thought to their chips (as evidenced by their inlay), and as such, I doubt they'd spend more, especially on the lower denom chips, just to have them 43mm.
There is a casino in Cali and another in Wisconsin that have most of their denoms oversize. Those are the only two I know of with regular chips that are oversize. There are hundreds of casinos with oversize chips for tourneys or baccarat or high denominations or sports book chips.