There are actually several chunks not missing but rather moved around an area of around 5 to 10 chunks. It happens to go through half of my storage system and Island house that I have. So to answer your question yes the chunks were there before. Since many spots have been relocated and left gaping holes in their place It has destroyed my storage system which transported goods through those chunks underground. If only there was a way to fix this, I would hate to spend my time fixing these issues rather than preparing for the upcoming update.
There are actually several chunks not missing but rather moved around an area of around 5 to 10 chunks. It happens to go through half of my storage system and Island house that I have. So to answer your question yes the chunks were there before. Since many spots have been relocated and left gaping holes in their place It has destroyed my storage system which transported goods through those chunks underground. If only there was a way to fix this, I would hate to spend my time fixing these issues rather than preparing for the upcoming update.
Also thank you for your response SuperCrafterz