Unfortunately, if it hasn't already been applied to your account, it will not be.
To quote Achronos,
[quote]At the time of Destiny's release, we made a best effort to grant accounts their legacy emblems. However, we're talking about matching between two different systems, with years old legacy data. While we tried very hard to make sure everybody got their emblems, if data was incorrectly linked or your history missing, we were not able to grant you your legacy emblems.
Unfortunately, this is a round about way of saying that if you don't already have them, you're not going to be able to get them. Sorry.
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