In a recent interview, Sigma CEO Kazuto Yamaki confirmed that the new Sigma 60MP three-layer X3 1:1:1 Foveon sensor prototype is currently under development and will be available later this year. The official announcement is expected at the CP+ show in Japan next year (2023).
Sigma's CEO also mentioned that the new sensor will not have a good low light performance, but we should expect excellent results in good light conditions:
The 60MP Sigma Foveon sensor with X3 1:1:1 technology was initially delayed and then Sigma started development from scratch:
Update on the 60MP Sigma Foveon sensor with X3 1:1:1 technology
An update on the development of the Sigma Foveon sensor with X3 1:1:1 technology
Sigma full-frame mirrorless L-mount camera with Foveon sensor delayed indefinitely