"Massive upheaval" refers to a situation where there is a significant and sudden change or disruption, often affecting many people or a large area. Full definition
Climate scientists think a perfect storm of climate «flips» could cause massive upheavals in a matter of years (scientificamerican.com)
The uncertainties around Brexit are causing massive upheavals in some sectors. (thecareeradvicecentre.com)
As I said in the comments on that post, publishing is going through massive upheaval over not only the formats of books to be published in, but over its ongoing ability to make money in general. (angelahighland.com)