The bulk of online sales I will bet are 5-10 dollar 532's and people wanting ready made, not the smaller DIY crowd.
If future projectors come with 1 big led pumping phosphors I will find a way to focus it and make use of it.
If it comes down to burning there is no need to pump a gain medium for pretty colors. Industrial lasers will do.
But I hope we see many pretty stage lighting diodes available, as well as the tri core multi color diode I as many of you have thought about, a triangle waveguide with a RGB emitter all in close proximity and aligned with 3 tiny quartz fixed focus lenses, or a bragg grate combined diode that has 6 pins.
We shall see.
The repurposed projector parts business will change in time, but there are many variables and no 1 person is going to run it all, I suspect more and more hobbyist will do more and more for themselves, but making things easy for people is value added, pressed, soldered, lensed and ready to use serves a big part of the market, just parts is more for the real DIY people and they will seek a bargain anyway.