This is an interesting concept, but as has been said, it does nothing to really change the playability of the golf course. Changing par only makes it look better on TV that guys shot higher in relation to par. Only for the US Open does this really matter.
One this this thread also misses is the fact that shorter courses, the kind we propose to change the par on, have generally shorter holes overall. A course that comes to mind is the US Naval Academy course, where I played for a few years. 6500 +/- yards from the back tees. Both par 5's are reachable in two, 3 par 4's are reachable by long players, GREAT variety on the par 3's, but then nearly every other par 4 is reachable with a wedge and 7 iron is the longest club I hit into any green, and only then because #1 plays 30+ feet uphill to the green. So, you can change the "par" out there to 67 or 66 perhaps, but what does it do? The best players are still flipping wedges into the greens in competition. So, that is the main issue with shorter courses. I mean, unless you start breaking "par" down to fractions on holes, like a 375 yard hole playing a par 3.6 or something....and of course that makes no sense at all.
But, how many of these shorter courses have any desire to hold major events? State level Am events are generally played at 6700 or so yards, same with Section level PGA events (or at least the state open qualifiers I have played were). So unless the course wants badly to host a US Open or PGA or other really top level event, then it doesn't make much of a difference.
EDIT: BTW, I put US Naval Academy Golf Club in my personal Top 25, so in spite of it being "short" I think its a fantastic course.