I would think its a little more complicated than just making all the shafts the same length. Adjustments to lie angle, swing weighting, loft adjustments. Bryson has changed the landscape for equipment, so I'll be curious to see what happens at the major equipment manufacturers. Have to wait and see if they offer some "same shaft length" options.

I agree with Gary that there is more to it than just length...

In order to get the 'gapping' distances workable loft and weight would need to be altered through a set, otherwise very easy to have clubs that provide not much distance (carry) change through the bag - not as easy as just cutting them all down to 37.5" long
DeChambeau is completely different in the lie angles being at 69º and different loft specs and loft gaps through the set plus the extra thick grips mean his swing relies more on body speed with arm speed without any real wrist set - most handicap players with a similar set wouldn't get any distance or indeed get the ball in the air - would hit it low and right
Don't think it will change the way irons are specced by the OEM's - was tried I believe some years back (1980's?) by I think Tommy Armour but they didn't really sell

I am currently getting single length shafts. Yes to be at true technical perfection, loft/lie/grip size/flex point/torque/weight distribution... Omg the list is endless and constantly arguable. You've gotta start somewhere. Every teaching idea invariably sets a goal for creating a repeatable swing, whether its 1-plane or 5-planes (think Furyk). Well all our golf tools are differing sizes and shapes with the only uniformity being a manipulated feeling called swing-weight.
Shafts are arguably one of the most important parts of the golf tools we use. Its also the most consistent variable common among all golf tools. By swinging we try to affect a repeatable action at the end of our golf tool. Same-length shafts help simplfy this pursuit of repeatable action.
Fewer stance adjustments; fewer ball position adjustments; fewer timing adjustments due to bigger swing length arcs.
Concerning the idea of distance gaps among clubs; thats silly. No one buys a non-customized set expecting equal gapping. ALL players deal with distance gapping every shot! Its called backswing takeaway. I dont invoke a full swing on every shot...Nobody does. So gapping is handled by learning and practice and results.
Differing shaft length, head weight, lie angle was an attempt to create the 'feeling' of swinging the same tool at each swing.
Single length shaft, single head weight, single lie angle is the reality of creating the same tool for use at each swing.
The gaps and distances are due to my club loft if choice and my swing takeaway.

I will be 70 in September and I guess that qualifies me as an older golfer and that thought never crossed my mind. I play in a senior men's league and never heard it mentioned from any of our members and I am classified as a youngster in our league, our oldest being 93. The "Little Rascals II" as were are known, play three days a week at a local municipal course built in 1927. Have not objections to the concept, if it helps you enjoy the game and play better, by all means use it.