According to this Imgur help page, it should be.
- Due to privacy concerns, EXIF data/metadata is removed on upload. There is no setting available to retain the data.
According to this post over on Meta, the meta data is indeed removed.
On the side note, I would also like to point out that imgur will strip the EXIF data once the image is uploaded to their server.
You can see for yourself, using a service like metapicz. Grab a link to one of your images, paste it in the field on metapicz, and click Go! You should see that all the meta data is gone.
However, if you post an image link from a third-party image hosting site, it would depend on the policies of that third-party.