I'm aware of the automatic generation of release notes, which is great. But as a consumer of release notes, and trying to answer the question "should I upgrade?", I would love there to be a section called something like "Incompatible changes". Somebody by hand created something like that for 2.0 (https://cwiki.apache.org/confluence/display/PIVOT/Major+Feature+Changes+Between+1.5.x+and+2.0). Most of that page discusses features, but you also learn important things like that WTKXSerializer was renamed and the Shape classes were removed. Changing Exception to Throwable in one API isn't nearly that big, but it would be nice if there were a way to somehow flag it for the benefit of code migrators, so that you wouldn't have to click on every single JIRA link to discover that one of them, only listed as "A Task's TaskListener will not be called if a Throwable is thown...", implies that you might have to edit your Task code.
(Just to be clear, I'm not complaining at all that you're fixing this bug – it's a pretty nasty one, really. I had a similar one where I discovered that if a query times out, your executeFailed method never gets called on Mac OS. Speaking of which, I wonder why I never filed a ticket on that.)