Although I am using no evidence right now since I am at work, but:
I am quite sure ANet mentions that anything applied to Heroes can not be recovered if a Hero becomes locked or otherwise inaccessible.
SPOILER!!!!
For example, in NF, when you lose Koss, the weapons you had on him are gone till you get him back.
/SPOILER!!!!
So when it comes to not being able to access Heroes, yes, ANet has mentioned it if you pay attention.
Its not readily accessible for that important of that information, no, but they are covered and if you were more diligant in read rules you would have noticed most likely. (Hint to ANet, make it more apparent next time

).
As for the "trap" for you to buy GWEN to get them back... um, if you desire to really feel the need to pay 40 dollars to get back some items, that, unless they are uber rare (which why would you give them heroes), you can obtain back for free anyways. Its not like ANet makes real money when you trade GW gold or get it normally...