Brian,
you are right there are some changes which are now backward compatible. That's the reason why we need cross-component cooperation from other maintainers to detect these pieces and potentially report them to upstream and see if they are willing to fix them. Another option is also to create a compat package for autoconf-2.69 for f35, but it can lead to a result, where some of the maintainers/upstreams will never use autoconf-2.71.
If there are any packages, which are already orphaned, do not hesitate to let me know and I will remove them. Also, if you are missing any package there. Autoconf changes have a huge impact on the whole system, so it needs to be properly tested and agreed.
Thanks for your cooperation!
Ondrej