The tag cloud should output a list
|Reported by:||afercia||Owned by:|
|Focuses:||ui, accessibility, administration||Cc:|
Ideally, the tag cloud should be marked up as a list (<ul>) also in the few places where it's used in core. Apart from better semantics, an unordered list would also allow screen reader users to know in advance how many tags are within the list.
The wp_generate_tag_cloud() already has a format argument that can be set to list, this change would require just a few, simple, CSS adjustments.
Places where to look: the editor screen Tags meta box, and Press This.
About the tag cloud used in the Add Plugins > Featured screen, see #40186
Ticket submitted at WordCamp London 2017 :)