The main python and perl toolchains were never maintained by GNU either. Python has never been distributed under a GPL license. I'm not 100% sure of the licensing history of perl but I think it's always been available under a non-GPL license (as well as being under a GPL license - at least recently - not sure if that was always the case).

This doesn't seem like a noteworthy change to the degree to which GNU/Linux is an accurate name... though there are lots of things I'd put more importance on than GNU in describing debian (systemd, for instance).

Edit: Looks like Perl 1.0 was under the following non-commercial license, so definitely not always GPL though that now leaves the question of licensing when debian adopted it, if you really care.

> You may copy the perl kit in whole or in part as long as you don't try to make money off it, or pretend that you wrote it.

https://github.com/AnaTofuZ/Perl-1.0/blob/master/README.orig