7.0 has a lot of new functionality and a few changes to the Kibana Plugin APIs.
Kibana management index pattern URL changes
Kibana management URLs pertaining to index patterns have been changed to accurately reflect their content, from
Impact: References to these URLs will need to be updated.
legacy response handler
In this release we removed the already deprecated
legacy response handler for visualizations. See Kibana Plugin API changes in 6.5 for more information.
legacyIcon from visualizations
The already deprecated
legacyIcon was removed and you have to use
icon on a visualization to specify it's icon. See also Kibana Plugin API changes in 6.5