The new 2.4 release differs from the 2.3.1 in the way URIs are constructed.
2.3.1: {tagRoot}/foo/bar : <uri>foo-bar</uri>
2.4: {tagRoot}/foo/bar : <uri>bar</uri>
I think the 2.4 way is acceptable, but there is no changelog or documentation explaining exactly how this URI is built.
Please update the docs to explain this for both earlier and current versions, thanks.
You are right, the change in the uri was not intentional but introduced by other unrelated changes (the support for multiple taglibs with explicit configurations and initial support for EL functions).
FYI you should be able to obtain the same result as for version 2.3 by esplicitely adding a <taglibs> configuration as explained in http://maven-taglib.sourceforge.net/m2/tldgenerate-mojo.html