https://www.warlockbrawl.com/forums/wc3-suggestions/phoenix-nerfreworkAlso, the Zombie mode have been suggested before but didn't really get any appreciation.
The major reason was because it required a lot of time from the developers that they didn't have.
Today Warlock is sort of it its final stages due to lesser popularity and seemingly even lesser time available from developers
( opposite goes for the Dota 2 version though )
If big changes like modes etc would be implemented, we would probably not see it in WC3 Warlock.