We have to graduate (leave beta) first. Sites can graduate without getting their own design, but the reverse is not true. The criteria for graduation, at least as of June 2015, are basically these:
- When a site starts to consistently receive 10 questions/day, we’ll consider it for graduation.
- If a public beta site does not produce consistently helpful content, and lacks the caretakers needed for flags and spam to get handled and our Be Nice policy to be upheld, it will be closed.
Source: Graduation, site closure, and a clearer outlook on the health of SE sites
Unfortunately, we're currently pretty far below the level of 10 questions/day. In 2017, we've received 34 questions so far, or about 0.8 per day.