If you’re gonna add the mythic+ trinkets, why not also add the delve trinkets if you complete them on +11?
Don’t really care about the difficulty, but I think actually playing with some of the delve trinkets on myth track might be better than some dungeon/raid ones. Specs with 1.5m cds only have house of cards this season, but all of a sudden that funhouse lens might be a competitive alternative, and don’t even get me started on some statsticks.
What trinkets do Delves have? I remember that I have been using a candlestick that gives a shield every minute (or was it every 90sec?). And another that gives Haste or Versatility to someone you heal?
Why not. That will show the Raiders… 
But in all seriousness, its not such a great idea. Some Delve trinkets are crazy OP. Even more than the Raid ones.
The only thing going for them is that they are very limited in ilvl, and are almost impossible to get on Hero level (the loot table is too big). If you were to make mythic versions of them, they would be bonkers OP.
So whatever Blizzard does (giving Delve dinars or not) they simply cannot escape the reality of the situation. They need to tune the trinkets appropriately.
And they need to do it NEXT WEEK. Because after the dinars come to live, any change they do will upset everyone that spent a dinar on something.
+1
I’ve been using https://www.wowhead.com/item=234217/funhouse-lens because I haven’t been able to get House of Cards, but for some classes this delve trinket might be even better so why not add it to the item pool?
Funhouse lens is pretty great, 9kish haste or crit stat at hero level for 15 sec
Crit is my worst stat technically but even then 9k of it is no joke, going from 16% crit to 28% crit is great on bosses for extra damage for 15 seconds is nice, lines up well with my eye of tyr > lights hammer (45s) and my AW (2m cd but every HP spender knocks a second off, it usually is between 1:25 to 1:40ish)
Turbo-drain 5000 is a pretty solid trinket off Delves, doing 2.5-5% overall damage with its high proc rate, can essentially be a permanent DoT on targets.
Wouldn’t use a Dinar on it though when there’s better from Raid and Mythic+.
If by op you mean competing for BiS in some specs with the raid trinkets then yes.
That was my point, since m+ trinkets are bad enough this season that even adding them to the vendor might not help some specs. On the other hand adding the delve trinkets will get them some powerhouses to choose from that we never had the option to.
And as a raider, I do not see much of a problem to playing with some good trinkets from delves for the last 2-3 months of the season.
Competing at VETERAN level. In mythic level they become OP. 
That is my point.
For an example:
House of cards for an enh shaman sims at a 7.37% damage increase at 665ilvl
Suspicious energy drink for an enh shaman sims at a 7.74% damage increase at 665ilvl
So yes, if you mean op that it will probably be better than a raid trinket sure. On the other hand, what’s the harm of having some actual competition and choice for best trinkets?
Multiple Delve trinkets would be BiS for some specs if they had Myth Tracks. Funhouse Lens, Mechano-Core Amplifier, Suspicious Energy Drink are all very solid.
I’d say go beyond that in requirements. Require Algari Delver (Any Role) III and Breaking the Bank.
Yeah one of those achievements is defeating a challenge that blizz said that it will be purely cosmetic, and the other excludes players that only focus on a single class/spec.
I think keeping it to just 11 delves is enough, since the other requirements (m+ and raids) are in line with that one (no need for alts, or to go for a cosmetic challenge).
But yeah apart from that my point was just to add those nice trinkets so people have more choice.