according to NEWS it was actually deprecated in version 1.8. So maybe it's time to remove it, instead of adding the warning (as Ralf so recently did)? In this case, it seems to me the resulting incompatibility (of not adding the file) is actually desirable because it will force the authors relying on it to make their licensing decisions explicit -- as they should have been in the first place.
http://lists.gnu.org/archive/html/bug-automake/2008-09/msg00035.html in which rms shares his thoughts on the matter. Thanks for the pointers. But I don't see rms saying that adding a COPYING file is ok: rms> It occurs to me that Automake could warn about the lack rather than rms> supply one. Or it could ask what to do in this case. "rather than" being the crucial phrase. (I completely agree with Ralf that an interactive query is not right.) Best, Karl