When a <math> element uses display=block, there is now extraneous vertical whitespace. Because of T182041, these generate empty <p></p> tags surrounding the element. Before, these didn't take up any space, but now, I see the following CSS being applied:

.mw-body p {
  padding-bottom: 0.5em;
  margin: 0.5em 0px 0px;
}

What's more, these empty paragraphs are not generated if the math tags in the wikitext markup aren't surrounded by blank lines, resulting in inconsistent spacing.

An article you can see this on is Booth's_multiplication_algorithm.

Related issues have been closed as duplicates of T360917, so this probably will be too, but opening it as a new issue to keep that one clean.