I just want to know why we can use the emblems of chaos space marines but whenever someone asks about chaos armor it always ends with a no. I just want to make sense of the decision. I understand that seeing a world eater working with a ultramarine wouldn't make sense for the game. 

If there is a chance that someone working on the game sees this, I love this game but it's a little disappointing that if I wanna play as one of the chaos legions I can change the color and emblem to the said chaos legion but still forced to use the loyalist armor. Please just let us use the pvp chaos armor that's already in the game in the operations  

The devs have already confirmed in interviews that Games Workshop restricts what they can and cant do.

This is likely something that GW have said "no" to.

That doesnt prevent it happening in the future, in fact I think there should be Chaos Operations fighting against the Imperium. But it wont happen short term.

It would be interesting if they one day make a Chaos op that switches everyone to their Chaos skins/loadouts like getting put on that team in PvP. Although they would really need to revamp the customization on the chaos side of things.

Playing as Chaos in ops goes against "muh lore". But somehow it doesn't go against lore to still wear their colors and emblems. It doesn't go against lore to have a Space Wolf and Pre-heresy Dark Angel running around with someone dressed in Black Legion colors and insignia. It doesn't go against lore to have a bunch of Smurfs cosplaying as different chapters.

A slight oopsie on some ankle armor though? Boy howdy they'll fix that right quick. Can't have any lore inaccuracies.