Thomas,
Back in the 90s, I had a course just miss the best new list on Golf Digest. They sent out the panelists rankings and comments in those days, and I was struck by the most common negative comment on that course - the Par 3 holes were too similar in distance. And, there was a 130, a couple of 160-170's and a 190. It seemed to me that the mantra for par 3 holes was "all lengths" and "all points of the compass" to differentiate them in golfers' minds.
That got me into a string of courses where the par 3 holes were 130-170-210- and up to 260 plus or minus. My longest par 3 (back tees only) was about 295, built right after the US Open at Oakmont which had the 8th at over 300, if I recall correctly. Anyway, I did have golfers tell me "I remember all of the par 3 holes" (especially those over 250, LOL)
I didn't always make the middle tees similarly long. From working at golf courses and then my design apprentice period, those that influenced me felt average golfers hated a 3 wood into a par 3, and liked 5 iron - maybe one 3 iron tops - at most. On par 3 holes, you can accomplish that with tee spacing and get both. Basically, for those who only hit a dozen or less good shots per round, the par 3 holes were their chance to get a "greenie." Or, put another way, they were the fun holes for most.
I am getting back to that concept as I age, designing more for fun than awards, rankings, or Tour Pros who will never show up. To quote my dad, "Golf should be fun.....Dammit!" And, as I lose distance, I find it is a bit embarrassing to be hitting hybrid to a 180 yard hole, and I'm sure many other older golfers feel the same, even if they don't say it out loud.....
So, maybe they are morphing to more standard distances from the old days (i.e., 1990's...I think before that they were typically 150-190 yards from the middle tees and the ultra long and short ones were products of/reactions to golf raters.