No, that is not possible since water is a by product of combustion of fuel (without WI), so by your idea it would happen even without it
But you need to re read the information:
This only happens with sustained high load testing, it is thermal degradation of the turbine housings due to insulation and massive retention of heat energy.
The exact same happens to stock FD3S twin turbo systems with their restrictive turbine housings and exhaust manifolds where the cast iron gets eaten away and melted exactly like this (no WI involved) especially after a crack propagates then reducing heat transfer to a cooler part of the housing. *with thermal bags- there is no cooler part of the housing!*
Once you have a piece of metal hanging in the air stream without the ability to "reject" its heat to another cooler bit, that piece then becomes over stressed and much hotter as a result, and it gets "eaten away" this is what happened to the central divider in the split pulse turbine housing, it simply could not reject the heat fast enough (due to the thermal insulation of the turbo bag) and under sustained high load testing that piece got literally eaten away.
Without a turbo bag's retention of heat this would not happen.