It is unusual to have a major number release for the Toolbox plugin with such a small set of changes, but it was an important release due to the changes to the shared library and a few smaller plugin updates.
Dev4Press Shared Code Library is an essential part of all Dev4Press plugins, and it has been developed more rapidly in the past year or so, with new major updates coming out every few months. And, it is important to have all (well, maybe most) plugins updated on time with the stable Library release to avoid potential issues with compatibility. Also, updating the Library from a few versions back to a new one can cause class changes and styling issues. So, Toolbox may get one more similar release after the Summer regardless of other work being done to it.
Version 7.2 includes an update to the KSES filtering tweak with added Basic Set of tags and attributes. There are many changes to the organization of functions, removing deprecated functions from the 7.0 version and adding new deprecated functions. There are many other small changes to the code, regular code cleanup, and tweaks.
To see the list of all the changes in this version, please check out the changelog. If you find any issues with the new version, please, report them in the support forums.