Super sorry to let you down man. This is the top priority right now for us, @cherian will track you and I’m updating people affected here: Downloaded new version, lost all my lists - #92 by phillryu
If you DO want to give the new Clear on iPhone a chance despite the lack of sync for now, I do think in your situation… if you happen to have a recent iCloud full device backup from before the release (January 8th), restoring it and then launching new Clear is likely to get you back your lists on iPhone. (Though if you try this, please turn off iCloud sync on your other devices or any old Clear versions, or quit/force quit them through the process.)