SS
I have just had a look at the 744 FMC control laws for V NAV descent and I would think the 378 must be similar. Amongst the mass of variables which it uses, is ground speed, which has to be that at the time of activation, so , presumably, it's using instantaneous winds. The profile is predicated on a continuous idle thrust descent unless modified by vertical profile constraints. This would, again, be modified, as part of the control law calculation, for any input of forecast TAI or descent winds.
Hope this helps