No I believe:
Wrathion backpack
Recruit a Friend backpack
Are both currently in the game and do NOT turn off main hand weapons these are backpacks - If the rules do not apply to them, they should NOT apply to covenant backpacks.
It is not logical to apply it to some backpacks and not the others.
To be honest I think it probably depends on what it is (which covenant back item) and what you are have equipped (weapon wise).
There are bound to be some that barely clip and others that are horrendous.
I think it was the bigass axe from the wafronts. But actually I’m gonna go see exactly what’s what right now.
This is the whole point I have been making.
It does not matter what you choose Blizzard is forcing it so that ALL mainhand weapons are disabled, regardless and irrespective of how much clipping is involved.
It is Only however choosing to do it for the Covenant back armor.
It’s surely less work to add a show / hide mainhand weapon at the transmog and to NOT force disable all mainhand weapons when wearing any covenant cloak.
I know, but I’m not one to be bullied out of topics 
I would like a glyph to put more weapons on your back as well.
You weren’t bullied, I rightfully pointed out that this topic doesn’t apply to you and that you are replying purely to troll those of us who want a choice that you do not.
You wrongfully asserted you had any right to choose who does and doesn’t take part in topics. You wrongly called me a troll and that does not go down well with me at all.
It also ensures I will keep an eye on this thread to see other posters don’t suffer the same abuse.
Nope. As far as I can tell no 2h weapon works, but I didn’t try that many. Both on vamp and lich back pieces.
It’s kind of annoying having to choose between a 2h weapon or a decorational back piece. I’m not sure why those things don’t take the colack’s spot and take the weapon’s spot but I think that if they add an animation for holding the weapon, like the brewmaster’s barrel stick, like someone suggested, everyone wins. Sort of.
How hard is it to understand that if there was an option to hide/show weapon, it would fix everyone’s problems with this update?
That would be an option, it wouldn’t take away anything from anyone.
What we have right now is a cornered, enforced “option” which is more of a choice that makes you choose between two cool items which is completly stupid. It doesn’t give you freedom at all.
kek,
I don’t mind if it keeps the topic refreshed at the top of the forums you should post more to this topic.
I also got all the validation and agreement from you when you posted a picture of GW2 wings armor with a mainhand weapon on the back at the same time.
I therefore accept you agree that both should be visible in WoW as they are in GW2 
I tend to hide cloaks on most of my characters but some of these new appearances might make me want to use them.
I guess we’ll have to choose for now, unless they change it.
If you want to tell yourself that, knock yourself out, I don’t care
I merely commented that I hope they continue to expand on back pieces and gave examples from other games.
I still suggest you use that feedback form to let Blizzard know you would rather be able to use both.
I have already done so, I think it would be great if you did the same
And by the way, the clipping is not that bad or I imagine it’s not. At least on the sin stone and the bone wings.
It’s negligible on the Kyrian wings also… I would attach an image, but the forums refuse to let me… Not sure why or how some others can?
It is worth spreading that amongst your fellow supporters though, it certainly can’t do any harm.
The funny part is that most cloaks,weapons clip through eachother already and you are not forced to hide one of them to have the other visible.
“Meaningingingful choices 
” - Blizzard
Ohh I thought since you are keeping an eye on this topic and have so kindly kept responding you shared the same enthusiasm for further customisation options in the game as you stated in an earlier post?
I would have thought that you would agree that adding this option to further customise the game was definitely something you would endorse?
You can set them up so both the weapon and the back thing are on your character’s back at the same time? Cause if you can I’d like to know how.
Also I think you need to get more forum levels or something to post pictures, you can post a link and someone might help you display it.
You can check them on the wowhead modelviewer…