I haven't actually tested this yet with an epic/70 item, but recently on my twink my brother deleted one of my BOE weapons I had equipped, and a GM restored it for me un-soulbound, I just equipped it again but then I thought - This could be done with an expensive epic after it gets replaced (Which has happened to me a couple of times).
If someone deleted/vendored/de'd a BOE epic that they replaced recently and could try this out, that would be awesome
If not, I'll see if I can get one of mine restored although it's been at least a month since I vendored one.