I think this is uncontroversial at this point, but I'll wait 48h for objections.
Just to be difficult - you added the DFSG paragraph prior to the bit about use-triggered obligations (AGPL and co) - the implication is that such obligations are "lower priority" to DFSG. For such an important thing, it either needs to be written expressly, or positioned after the bit about the board decision wrt use-triggered obligations. There should also be a part where the TNF board is the final arbiter, if there is a lack of clarity.
--- license.mk.~1.90.~ 2018-12-08 10:18:38.000000000 -0500
+++ license.mk 2018-12-08 10:31:22.000000000 -0500
@@ -72,6 +72,12 @@
# ACCEPTABLE_LICENSES; the point is to have a default that very
# few people want to shrink.)
+# Licenses approved by Debian as meeting the Debian Free
+# Software Guidelines will also be added by default. They
+# should be in a second section with a comment about each one,
+# because Debian does not publish an accepted license list and
+# acceptability must be inferred from inclusion in main.
# As an exception to the Open Source or Free policy, the board
# of The NetBSD Foundation has decided that licenses that
# trigger obligations from use (rather than redistribution),