How come we never got Warp Ammo or Lift Grenades added to the game?

Since there are barely (or if any?) biotic primers in this game, I'd be happy with AP or Phasic Rounds.

Warp ammo primes, the asari would detonate it with Throw or Lance etc...

I think the phrasing of your question might be obscuring the purpose of your question.  Would it be more accurate to ask "Why were Warp Ammo and Lift Grenades not included at launch?"  Slightly different question but puts emphasis on the exclusion of these items from the beginning.

ME3 Warp Ammo did not prime. It gave bonus damage against armor and had a further bonus against targets that were primed by a biotic ability.

That said, even if it had primed it wouldn't have been detonated by Concussive Shot. With very few exceptions (e.g. Throw detonated tech bursts and, I think, fire explosions) biotic/tech/combat abilities did not detonate cross-class primers.

Ahh the good old days when priming and detonations made in universe sense and respected lore rather than being overly simplified and dumbed down to the point of absurdity.

Warp ammo was crazy powerful but it wasn't interesting. Mainly it was just rage inducing, as there was always someone detonating my huntress's dark channel or warp on the banshees/etc. Your detonation is less important than my warp ammo-warp/darkchannel-reegaring.

Because they spent 3 years jerking off to proceduraliy generated planets and landscapes instead of making a game. And by the time anyone with any sanity checked on them it was too late to do anything other than patch the mess up as best as possible, push out the resulting "game" to idiots like me who preordered based on their reputation, then move the few good employees to other divisions, fire all the rest and then run screaming hoping we'd all forget the ass fucking we took.

hey now the mp isn't that bad, I mean sure its got a few bugs and the remnant are cheap bastards but its playable (when the host isn't some kid using a potato) the single player is just boring but again still very playable (even if the storyline makes little sense and the missions are all out of whack) the world maps would be a lot better if you didn't insta die by magically crossing some invisible line before you "unlock" that zone.... and a few other problems...

I mean visually the games nice, the combat isn't dire ok the gear progression is just garbage (I thought me2's planet scanner was boring but this game takes the cake on that one)

but the stuff in the game is nice to look at and having spend more than 50 hours playing the sp game I think I can say It was worth the pre order price tag much more so than some other games have been (halo 5 took less than 5 hours to play through the first time, and only another 8 hours to generate most of the medals but cost the same amount.....) and hey my game came with a free mug and matchbox car when I picked it up in store ...... of course the mugs just a standard tin one with black paint that started to peel off because the kids use it but meh the car at least still looks like new (amazing since its in one of the toy boxes) 

thing is if they make a new mass effect game i'll probably buy it especially if its in the milky way, hmm actually so long as it doesn't include wall eye as the protagonist i'll buy an new Andromeda game as well and hope they managed to find a script writer and some people who can actually do inspirational voice acting (rather than sounding melancholy, tired and breathless all the time, that shit made me want to slit my wrists... urrgghh) 

My thougths exactly when I read that OP