For some of us - the extra step of overcasting raw edges before putting the fabric in the wash is worthwhile - there is no tangle of unraveled threads to cope with - and the fabric 'loss' due to fraying is zero when I overcast with my serger - I can remove the threads fairly easily - and the 'loss' when I use a narrow zig-zag stitch with my regular sewing machine might be 1/8 inch on each end.
I've been hearing that the price of some fabrics is as high as $15.00 per yard at some stores? - it seems worth while to conserve as much of that fabric as possible - I have seen fraying loss of over an inch on each end. (From LQS fabrics!!!!!!!!!!!!!!)
The reason for the hot water wash and high heat drying - it maximizes the shrinking. I only subject my fabrics to the hot water SOAK once - I believe the agitation is what makes fabrics look 'worn' - and I do dry my fabrics on moderate heat - that minimizes the setting in of wrinkles. I leave room in the dryer for the fabric to fluff up - and not be mashed/wadded up in an overloaded dryer.
I've also found that many fabrics are smooth enough to fold and store until ready to cut. When ready to cut, that seems like a logical time to press/iron the fabric and/or apply starch/sizing if you are one that starches.
It seems like this topic has been discussed a zillion times - those of us that think washing the fabrics before cutting them is worth the effort will probably continue to do so -
Those that think it's unnecessary will probably continue to think it's not worth the effort.
Whatever.