My guess is that both fountain and it's shrink that were actually GE level 4 buildings were planned to be included in the level 4 pack but that would clearly have been a mistake and way too easy to obtain. In my opinion a good compromise would be adding 150/200 frags of each in the level 4 pack to chose from to keep the fountain of youth shrinks alive.
The issue now with how hard, and so few a Year, shrinks are obtainable it will actually speed up the time it takes to finish your WW/FoY cities and simply start new ones. It's actually the shrinks that slow down the progress. VF with all expansions can fit 400 shrunk WW/FoY but without the shrinks you are looking at 250 WW/FoY withut buying the last 12 diamond expansions.
Nobody is going for shrinks if you can only get a couple a Year and simply go for full 3x3 setups.