An explicit restructure causing block sizes to more than double in some cases?

Summary:

Running an explicit restructure on BSO cubes caused the block sizes to increase (greatly in some cases). Why is this occurring?

Content (please ensure you mask any confidential information):

I just cleared a large amount of data from our BSO and ASO cubes in an application. I was monitoring the block sizes of the BSO cubes as I went and as was expected with clearing entire Scenario/Version combinations I saw the block sizes of each cube go down as data was cleared. When I was finished I did a restructure of the cube (just general maintenance while I was in there) and saw the block sizes of the BSO cubes shoot up. As an example, I had one cube that started at 1,238,322 level 0