The idea is that a large-scale LH2 flow into the system is being consumed, and perforce heated, and may be used as refrigerant on the way there. It makes perfect sense.

Rockets do this today, as indeed they have done from the earliest days, sending liquified gases through channels in the engine bell and combustion chamber before burning, keeping them both from vaporizing.

Here, the very high efficiency of electric-driven turbines is offset by the lower efficiency of fuel-cell generation, for what is expected to be a substantial net gain over burning H2 in internal combustion turbines.

The latter are the obvious first stage of deployment, taking advantage of LH2's extreme energy-to-weight ratio for reducing the takeoff fuel load by as much as 5:1. This form will probably be fielded in existing airframes, displacing some cargo space with in-hull LH2 tanks.