Man, I hope not. One of my favorite things about DG is the overwhelming diversity of courses/designs out there. Granted, for every one great (IMHO, as everyone's definition of fun/great is a little different) course, there are 4-5 stinkers (and 8-10 "yawn"). But I enjoy seeing/playing different people's visions for a hole/course. And not every parcel of land lends itself to
PDGA Book of Everything, Volume 23, Chapter 806, sub-paragraph C, sub-sub-paragraph XII, line 463
It'll be OK. Think of the history children's play structures. You may not remember, but at one time they were built by plumbers who welded pipes together at right angles and set them in a concrete base. Some of those plumbers had some creative ideas, but we don't miss those days.
After safety standards for play structures were introduced, for a while all you saw was the same colored plastic slides and ladders over ground rubber bases.
But now, there are fiberglass molded structures that look like boats, treehouses, or mountains and have climbing walls and all sorts of things to target specific skills.
We've still got courses with tee pads that have a 6 inch drop off the front edge. We're in the metal pipes on concrete phase.
There may be a blandness phase, with blah designs coming from consultants that don't want to bring in a designer. But great courses will still be built because the enlightened consultants will bring in the top current designers.
There just won't be any more stinkers.
Also, the big money will enable things we don't do now, like earth-moving, massive plantings of native species, artificial turf for high-impact areas, sun and rain protection over the tee pads, cart paths, automatic disc return at driving ranges...
And the quantifying of the sport will lead to the insights that will allow the development of the tools needed to take course design to a whole new level. But that will require a formal structure to capture, teach and build upon the knowledge generated.
(By the way, I don't think it will be the PDGA that writes "the book" on truly professional course design.)