To help reduce the need to use an epoch later, I think we should recommend packages with date-based numbering use a version number prefixed with something like 0~. For instance, the current version of fonts-noto-color-emoji in Debian is 0~20180102-1. This could possibly be a Lintian warning if a date-based format is detected for a new Debian package.
Some packages can avoid the use of an epoch by using an epoch only for the specific packages that need an epoch by manipulating dh_gencontrol. For instance, this is done in fonts-ubuntu to use epochs only for the transitional packages (which we'll be able to drop in a few months). https://salsa.debian.org/fonts-team/fonts-ubuntu/blob/debian/unstable/debian/rules This trick is probably only useful when a package changes names (like gcompris will probably become a transitional package depending on gcompris-qt soon and only the gcompris package needs the epoch). Thanks, Jeremy Bicha