Yes climbing the scales is much easier but if he had not climbed the scale on the 70s endings it would have been an odd ending-hitting it dead on. For opera the dead on high note would have been correct but since Elvis's "Its Now or Never" was not true opera- the climb is more pop, IMO, and it makes the crescendo more exciting. On "Surrender" he hits the high note on the word "to----night" coming back down on the second syllable "night" I think Elvis could have sung either like a straight opera singer if he had worked at them-but he(and we) would probably have not liked them nearly as much.
I agree Elvis was a fine ballad singer by the 1960 sessions. I'm just not sure how confident he was in his own ablilties as a ballad singer. One of the Imperials said Elvis's voice climbed higher in live performances than his normal range would usually allow. He said he attributed it to Elvis reacting to crowds and the excitement of live performing. I guess that is the part that attracts me to the live version.