I would not say that there are many new projects that launched close to halving, I would rather stick to idea that projects appear on an uptrend market. Limiting it with halving makes no sense, because after it, new projects will still pop up frequently. But why more of them appear during uptrend than during downtrend? Answer is simple, big money can attract other big money. Some of new projects are scam and try to hide among real ones. Some hope to get attention while investors rush to share their money. On the other hand, when else should projects be launched? When market is red or during stagnation? Brave move, but silly.