We do not plan to put the random-stat Accolade trinkets on the vendors.
However, we did uncover a bug that was causing them to provide twice the secondary stat bonus than was intended. That bug was corrected in patch 6.2.2.
Frankly (speaking for myself as a player, and not for the development team), I'm not convinced that the Accolade trinkets are all they're cracked up to be.
The Wild Gladiator's Accolade of Dominance provides 403 Intellect and 403 Versatility in PvP combat. The Insignia provides 469 Versatility and a 20-second 1330 Intellect proc. In sustained combat, it tends to proc around every 60 seconds, giving it roughly a 33% uptime for an average benefit of ~440 Intellect.
Combine that with the fact that you have to actually be damaging someone for it to proc (which increases the effective uptime by cutting out sections where you're not hitting anyone) and the increased burst potential by allowing you to use your hardest-hitting abilities while it's active... and I'd argue that for the vast majority of players the proc trinket is easily better.
Granted, you might want a different secondary stat which isn't available on the Insignia. In that case I would argue that the difference between 469 Versatility and, lets say, 403 Mastery would be EXTREMELY minor at best.
I could also see an argument for those who are playing Humans, in which case you'd likely be comparing the Accolades to the Badges (the on-use trinkets) instead of the Insignias. As you can probably imagine, buffing Humans isn't exactly high on our priority list at the moment.
All that said, I won't pretend for a second that I'm the best Arena player, and these are obviously just my personal opinions. I'm just not seeing what makes the Accolade trinkets so incredibly attractive that they're absolutely mandatory to the point that it's worth doing content you don't enjoy for a chance to get hold of one.
I'm not really defending RNG PvP gearing, and I think the actions the development team has taken since 6.2 released speak pretty well to say that the devs aren't happy with the way it worked initially either. And I totally understand why it's frustrating that those actions aren't extending to the Accolade trinkets. All I'm saying is that, if you really don't like Ashran, just don't do it. There are other trinket options, and they're -- at worst -- still pretty good.
EDIT: I should also mention again that I'm really only speaking on behalf of myself and the way I enjoy the game. Just trying to have a conversation here. :)