Still, this is just poor form. Especially on a point release with no prior warning. This will definitely take most users *far* longer than five minutes to fix. Or even to figure out why it’s broken in the first place.
The best worst case scenario would have been for you to think about the effect of such a breaking change and write a little updater script that people could use without having to install another plugin or figure out regex/search & replace tools.
Kudos for ripping the bandaid and making the shortcode unique. But, you have to remember that most plugin users are not web devs or even understand how WordPress updates work. It is this kind of breaking change that average users about ever performing updates in the first place.
Either way, thanks for being present and at least providing solid support after the fact. And thanks for your work on the plugin! It’s a hard road to build & support free plugins.