There’s two parts to this;
When kochobo’s hinamatsuri targets a monster, and that monster leaves the field before hinamatsuri is summoned, it will still copy the level of the target. This might be correct but I’m not sure, couldn’t find direct rulings on that.
The weirder part is how it interacts with temporary removal; SP being chained in response to get that target temporarily off the field ends up in a state where that target returning to the field ending up with halved attack, even though the attack halving would’ve applied when it was off-field. This one is definitely wrong