It seems that it is a factory for silicon wafers, which together with "Smart Power" suggests that the main products will be integrated circuits used as controllers for various kinds of power converters and power supplies.
Nowadays, silicon has become restricted to the applications under 100 V, the power devices for higher voltages being preferably made of gallium nitride or silicon carbide.
So this fab is likely to produce controllers for power devices that Infineon makes in other fabs.
Now Infineon has a problem, because they have just been forbidden by China to export gallium nitride devices there, because apparently their GaN devices infringe a Chinese patent. Previously that was an important market for them.
It is said that the opening of this new fab has been advanced by a few months in comparison with the original plan, supposedly to take advantage of the increase in demand for power supplies in AI datacenters, so that the expansion in this new market would offset the loss in the Chinese market.