My guess is that the discontinuation of the trem has to do with James Valentine’s current preferences more than anything else.
That could be true. I think when they first put the trem versions out, JV was saying things like "a lot of guys were asking if they could get a trem version" and implying that he wasn't personally much of a trem guy.
On the one hand, I like how EBMM handles their sig/artist guitars, really honoring the artist's specs and preferences. When JV switched from 11 gauge strings to 10's apparently, all the Valentine specs were changed to now ship with 10s on them, etc.
But on the other hand, I have two James Valentine guitars and have never owned a Maroon 5 album, nor will I probably ever-- though James Valentine seems like a super cool guy. But the JV is just a fantastic instrument in every facet.
I do own five different signature guitars now that I think about it--which is weird because I don't really play much like most of the players for whom the signatures were made. I imagine a lot of people who buy a Majesty just crack open the case and sit around playing "Pull Me Under" on it. Eh... Not for me.
I'll say that since getting the Valentines, I have maybe changed my playing style to a more percussive, rhythmic style maybe with some elements of JV or Cory Wong or The 1975 style of guitar playing. Ironically, the guitarist from The 1975 often plays an EBMM John Petrucci guitar that he'd originally bought with some inheritance money--and he found that the middle position pickup sound actually worked uniquely well for a clean, funky rhythm tone. The 1975 and Dream Theater have nothing in common-- but that's how I like to see a signature guitar being put to use.
I don't know why it would really bother JV if EBMM were to make some extra bucks selling the trem version (which was already in production). Albert Lee really wasn't the driving force behind the HH version of his guitar. So many other guys loved his signature guitar and wanted an HH version and from what I gather EBMM asked him if he would mind if they released an HH model and he was fine with it if it helped them sell more guitars-- which it did. Supposedly the HH versions way outsold the SSS models.
As for the idea that the trem versions didn't sell... I would have bought either of mine as trem versions if that's what I ran across-- it seems like the trem versions were just less common. I do like the stability of the hardtail, but if given the choice, I would have taken the trem at the time. I could always block it off if I really didn't want to use it.
Anyway that's my rant for the day. I hope the OP gets a Valentine and bonds with it the way I have with mine.