In theory, yes
BUT
I runs my beds east to west too :)
The first year I sowed religiously in faffy short 1m rows north to south, but this year I have easier, long rows, east to west.
For most crops, the s'wards rows matured slightly earlier, and the n'wards ones slightly later - effortless succession and longer cropping :D Others like onions and leeks are planted in blocks, so it doesn't matter which way they are facing.
I made a mistake planting tall PSB half way up the plot last year, and rows of overwintering broadies to their north - the beans all suffered from lack of light and few survived the winter :'( Now the firm rule is to sow and plant tall crops in the north, short ones in the south. I bet any landscape gardener would know that :-[
It sounds like it's sensible to run your rows like you do, across the slope. That way they all get comparable soil conditions and rain. That's what most civilisations faced with a slope have done - all those Mayan/Japanese terraces :o
If you're keen to experiment, you could try a little patch? I have this year, and it seems to make no difference to the quality or yield, so I'm sticking to my (east to west) layout ;)