Why can't just leave the fridge space without top cabinet?
supposedly, the top cabinet (for those who do) above fridge is mostly for feng shui purposes, or for aesthetic purposes, given that it's not the most convenient to access storage space
depending on user's time frame, for someone not looking to move house in the next 15-20 years, it will probably make sense to leave some extra allowance - the space can be easily filled, by multi-tier rack from Taobao (those that are intended to fill up narrow spaces in kitchen), this obviously is an easier (and cheaper) problem to solve, than ponder over which replacement fridge model to go for when the space is constricted due to existing carpentry setup
whether the fridges in next decade will become larger by lateral size, or height, is anybody's guess
one can be as perfectionist as possible now, and customize carpentry to fit to perfection, and leave the headache of changing fridge for another day
or try to future-proof and leave some space allowance (and make the potential future headache smaller)