I recently did some exploration over 2000 blocks (one level 4 map) away from spawn. When I first created the world, I actually spawned in a village, and I have since modified the village to more than triple its population.
When I came back from my exploration, I think another bug despawned several villagers. It had to be several because the population was 62, and there are 51 beds.
Needing XP to repair my gear, I decided to grab crops and paper to trade with the villagers. My farmers were not all leveled up, so I did buy some bread. I eat cooked beef exclusively, so being charitable I threw the bread back to the villagers. Big mistake.
Now that the villagers had enough food, they went insane. Love everywhere. 1 child. 2 childs. 3 childs. 50 childs.
Over the course of a day, the population rose from whatever it was initially to 149. It essentially tripled in size despite only 51 beds existing in the village. Significant lag ensued.

I did some experiments, and in creative mode I got the same thing to happen by killing 11 villagers, since the old save hadn't despawned any of the original 62 villagers. Population over 100.
I think the issue could be related to either the bugs involving villagers to not link properly with beds, or the bug that currently affects their navigation, especially along the Y axis.