I've noticed while playing in single player worlds that chunks take a really long time to load/generate, this happens either if the player is traveling by foot, horse, boat, or elytra ( flying with the elytra has become impossible at this point).

The same thing has been happening in multiplayer worlds and online servers.

In my personal experience, it seems that it's worse in online servers, the maps will simply not load making playing in servers impossible.

I'm not sure why this is happening with this latest update, but I think that the way the chunks "fade in" is contributing to the problem.