In my (not so) humble opinion, 14.10 is an EOL release, so questions about that particular version itself are off-topic, but questions on how to upgrade are not.
In this particular case, I don't think BQ will unpack all phones in of their warehouse and upgrade them to 15.10 before shipping, so in my humble opinion, we should reopen this question and then protect it...
That way, we can let this be the "one" exception: all other questions related to upgrading can then be closed onto this one! (thanks @Rinzwind for the tip!)
#:-)