As a machinist my personal thought is...for a bone stock rebuild a torque plate is not needed...BUT if you have any future goals of big power about 500hp a plate would be wise!
With the amount the arp or stock bolts stretch I can only see the block deforming .0003" if that...considing on a compression and ignition a cylinder expands ruffly .003" that .0003" isn't going to effect much....in my opinion.
When you start trying to push motors to insane amounts of power everything starts making big impacts on everything else....that's when small shit like torque plates start to shine....that's when a motor may blow if you fart at the wrong time and push the motor over the edge.
Again that's my opinion....I'm in no way a profeshional on this...the only thing I can relate to is parts I've made that spin well above 100,000 rpm etc.
And last I checked Toyota didn't use them either.