Tony:
I haven't seen LACC since the restoration, but I've done restoration work elsewhere, so I have thought about this subject a fair amount.
Firstly, you know as well as anyone that evolution is always ongoing. If the club has left its course alone for years, it has not achieved stasis ... it's still evolving, and always will. These new bunkers will evolve and change over time, but not necessarily the same way they did before.
Secondly, evolution does not necessarily yield a better result than what has come before. It is only the product of natural processes.
Third, natural processes do not account for everything on a golf course. In fact, much of the "evolution" of any course has been the result of DELIBERATE changes by architects, superintendents, and green chairmen ... none of them necessarily wiser than the original architect. In fact, all of the greens and greenside bunkers at LACC were rebuilt and changed just a dozen years ago; they didn't look like the 1925 version in 1990, but you could make a case for the recent changes being a correction of that work, and other work performed deliberately in the past.
How does one preserve such changes? They will only be preserved according to the skill of the superintendent and the will of the membership ... unless Geoff S. is going to go out there and do the spade work around the bunkers himself, gratis.