Ask Different doesn't seem to migrate many questions anywhere very often; in the last 90 days, 7 questions were migrated to SO and 1 to SU (and 6 to the child meta).
Migration paths are only created when there is a history of many good migrations having happened between site A and site B.
Source: Can we have StackOverflow added as a site we can migrate questions to
There hasn't been a migration to UX in the last 90 days (I can't go back further in time, but I don't recall any others that have been migrated).
You can always flag for a moderator to migrate it though:
you can flag a post for moderator attention and a moderator can migrate it to any SE site if it needs to be moved
Source: Closing question as should be on other SE site
With regard to the specific post in question, I saw your off-topic flag and voted to close the question with a custom reason (which you can do at 3k)—you can see the reason that I gave as it is added as a comment: I mentioned UX as a possible destination to the question. If the question is closed, the user is free to ask the question on UX anyway, if they wish, or request that the question be migrated themselves by flagging their own question.
In this case, as your off-topic flag doesn't 'count' it doesn't really matter which reason you give, as the reason for the closure (shown in the blue post notice) will be determined by those who actually vote to close the post (whether that be 5 users or a ♦ moderator) rather than those who have flagged as off-topic. Your flag simply brings it to the attention of other users who have greater than 3k reputation. When you reach 3k, you will be able to cast your own votes to close questions (and also view the Close Votes review queue). You will then be able to write a custom reason in the free-form off-topic box which can be used as the actual reason for the closure:
