Usually higher alpha equates to higher oil content.
I'm not sold on the idea of pre-chilling the wort and then hopping in the 60's. Think about how most brewery's pump straight into a heat exchange at the end of the boil, this process is something only homebrewer's would come up with. It is an inelegant solution, and introduces another avenue for infection.
Put a lid on your kettle to condense the essential oils once you've dumped the hops into the whirlpool, or invest in a hop-back. Most of the compounds which contribute to beers aroma are simple hydrocarbon derived terpenes, which are relatively inert to pH 4 and a bit of heat.
Provided your boil was long enough and vigorous enough, condensing other volatiles such as DMS shouldn't be a concern.