Now that Stretch has been released, the Perl modules that I am an uploader for and for which there have been version updates waiting to be packaged can now be worked on, either by me or by others of the Debian pkg-perl team. This included the following 9 packages:
Checked the debian-policy package again on 20 June & found that 4.0.0-1 is now in unstable, so will be updating that in the packages I do.
Noted during a pkg-perl LHF (Low-hanging fruits) session in IRC debian-perl that both the Standards version up to 4.0.0 as well as debhelper to version 10, were getting updated. Checked the debhelper package in Debian and Ubuntu; 10.x is in stretch as well as jessie-backports (but not jessie itself as it only has 9.2x), as well as yakkety (16.10) and xenial-backports (but not xenial itself as that only has 9.2x). All in all; it looks like it's better to also move them to debhelper 10, and if there are any issues with building for older distributions it just won't be able to do a no-change backport to them.