With the new start menu, I decided that I ought to rework some of my old templates.  I started off with one called "! Pop-Rock" (because exclamation mark sorts first, forcing my template to appear at the top).  When I saved it and looked at the start menu again, it had a thumbnail of a cherryburst Les Paul.  (which happened to be the same as the one for Electric Guitars in Rapture Pro).
 
I made another one called "! Electronic".  The first time I saved it, I saw a thumbnail which looked like an open project.  The second time, it had a thumbnail of a keyboard attached to it.
 
I saved a couple of other projects.  These have a simple "CWT" thumbnail attached to them.
 
I am curious why it would be doing this.  I also would like to know if there is a way to specify which images I would like to be associated with a template.

Can't say for sure, but my guess is that the "!" is causing this (has a special meaning for those doing the programming). Kinda like using the "&" key can cause some programs to place an underscore under the next letter. What you might try instead is "01 Pop Rock", "02 Country", "03 Classical" as your sorting system and see if that solves the problem.

Well the developer did not accommodate for UTF (foreign language characters) for project file names,so it would not surprise me at all that he/she didn't accommodate for allowed characters away from the norm in the file path. QA should have picked this all up as well (my opinion). There are too many issues with it (sorry my opinion) so I'm leaving well alone.

That doesn't seem to be it.  I renamed the template to 000 - Pop-Rock and got the same results.

I found this...seems to be some "smarts" in the start screen that uses the template name to determine image (so genres get picked up and a hopefully helpful image appears).

I noticed the pattern too where the template name seems to determine the image. I'd love to be able to specify a unique image for each custom template.

Magic Russ
That doesn't seem to be it.  I renamed the template to 000 - Pop-Rock and got the same results.

A dash is standard ASCII. I still haven't tested btw.

I saved the Pop-Rock template to 000 Rock, 000 Blues, 000 Jazz and all had the Les Paul.
 
I saved the same template as 000 Metal and the three amps appeared.
 
I saved the same template to 000 Electronic and had the keyboard.
 
When I saved with Country, Rap, Hip Hop, EDM, House, Trance, Songwriter, Folk, Techno, or Acoustic in the title, it resulted in a thumbnail of the project. 
 
@Dranck - I agree, the ability to associate an icon with the template would be great.

After saving some of these a second time, I am getting an acoustic guitar for Songwriter and a keyboard for EDM.  Also, for some others, the project thumbnail is replaced by the default CWT image.

nice to have monthly updates to tweak new things...