My take is centering the European impact because we are discussing European policies. If we strip away your concern trolling, what you're saying is that EuroCentric nations need to have a rule of law and strong immigration controls to deal with the influx of, in this case, Haitians because natural disasters there cause an influx of immigrants from there.
First of all, the idea that figures like Moïse and their impact is purely Haitian agency and has absolutely nothing to do with the long history of European oppression is totally ahistorical and attempts to paint a "both sides" sort of apologia for empire.
But second of all, bad leaders and natural disasters do not cause mass international migration in the imperial core countries, so why does it cause it in places like Haiti? It is because Haiti has been over exploited and had its ability to develop effective self governance undermined constantly by European intervention.
And finally, even in those situations where a self-governing, non-over-exploited Haiti experienced a natural disaster that caused significant displacement, is that really the reason the US needs strong immigration policies? And to be clear, strong immigration policies under Biden literally meant Haitians being whipped by white cops on horseback.
You can keep acting like what I'm saying is that Haitians are not self-determining, but that's not what I'm saying at all. I am saying that the self-determination of Haitians is happening within a context of abject white supremacist violent domination and oppression by Europeans which has occurred over several centuries in a coordinated effort to subjugate the people of Haiti and their neighbors and friends and simultaneously insult the people of the imperial core from the backlash created by this domination and subjugation both physically and narratively.