Why not? Rangers just have riflemen dialogue and the US commander's response to calling them is simply "Acknowledged". Flammenhetzer has no new diologue either afaik.
Still, they were recorded and the whole concept of these units were designed when they were working on WFA. And it still sounds lazy to hear some generic voice lines. They should have thought about it way before. Rangers have complete voice lines because they were recorded for AA campaign.
they could always hire a new or even the old actor..
would cost too much i guess
They could but they won't.
If money was a problem, they'd just get Kyle to be the voice actor.
Well it's not only about the voice and the money. Here is the thing:
Generating new content for a video game is not that easy. All of your departments should work on the said content (Gameplay design dept., sound dept., 3D dept etc.) and it means they should stop working on what they've been working on and shift their effort on the new content. As far as I know, all of these "new contents" were created during the actual production time (Vanilla CoH2, WFA, AA, TBF) and the community dug them up from the game files. They just waited and delayed the release time as a marketing strategy (which is cool if done right, keeps people excited and everything).
All I'm saying is, it's not like "Hey guys let's add KCHs". There are a lot of consideration. I would love to see KCHs along with a lot more units (FlAK, Geschützwagen, Hummel, PzIII, Motor Cycle, Hotckiss, etc) but I think this is unlikely.
Unless Relic decides to halt their production and dedicate some time and create a new DLC pack worth selling (with a lot of units).
Oh, and as far as I know, hiring a voice actor isn't that expensive. Even famous voice actors don't get paid too much (unless they are in Hollywood).