That doesn't seem to line up well with Turchin's secular cycle theory, though: 1300 is supposed to be the peak of the "integrative phase" and 1400 is supposed to be the trough of the "disintegrative phase". In fact, many of the "disintegrative phase" events happen well before 1350 (the Great Famine of 1315-1317, the Shepherds' Crusade of 1320, the Flemish peasant revolts of 1323) and many of the events that happened after 1350 could be explained more simply as effects of the Black Death.
To be fair to Turchin, I think his thesis is that overpopulation and elite overproduction happens first, which then leads to famine/scarcity decreasing the non-elite population, which finally leads to a later period of warfare that kills off the excess elites as they fight for shares of the smaller pie. But I think the claim that this process happens for all societies on a 200-year sine wave warrants some skepticism.
But that might also be due to the end of the warm period and the start of the little ice age. For reference: Its about now that the norse have to abandon their Greenland settlement.
As you say though a bigger factor was Portuguese traders gaining access to African elephant ivory which was easier and cheaper to procure than walrus ivory which was the cash crop of the Greenland settlement.
I feel like you need to mention the black death in this same sentence though, as the nobility population change would arguably be a lesser factor in thrall to that massive event.
It does certainly paint an interesting aftermath as the black death suddenly made life a valuable commodity leading to a small period of time where worker's rights and even in some cases women's rights were improved. Considering that against a backdrop of indignant nobles is entertaining ponder-thought.
The Great Famine was 1315ish, were you thinking of that instead?