On May 28, 2017, the official CCLP4 logo was revealed, as well as a series of leaks on the CCLP4 site for the set's upcoming release. They are as follows:
1) The lowest time limit is 60 and the highest time limit is 999. 2 of the 3 levels with a 999 time limit are by the same designer.
2) Two community-nominated levels will appear in the final set.
3) The highest and second highest rated level for "fun" in CCLP4 voting were ranked 152nd and 588th in CCLP1 voting, respectively.
4) Two levels are in the same slot as the level their walls were originally from.
5) Nine of the twenty eight levels showcased in the first podcast did not make it into CCLP4. Four of the levels in the second podcast did make it.
6) The 131, 144, 147, and 149 spots are held by four different CCLP4 staff members.
7) The most consecutive levels by the same designer is 3. This occurs four times in the set, covering three different designers.
8) The highest fun rating not included in CCLP4 was 4.35. The lowest fun rating included was 3.33.
9) Thirty-six levels do not contain blocks. Three additional levels use blocks only for aesthetic purposes.
10) Four levels have been significantly renamed. The new titles are Inferno Dynamics, Detonation Station, Ruinous Plaza, and Blockpick.
In addition to these leaks, a special video titled "Monument" was released, which gave various clues to who had levels in each CCLP (including CCLP4), and so on. It revealed that CCLP4 would consist of levels by 21 different designers, 5 of which never contributed to an official set and that a single designer will have at least one level in every official CCLP.
Later, a special dispatch message from the CCLP4 clubhouse also revealed that walls from levels previously seen in official sets would be reused in the set.