Bah, nevermind; the upstream gettextize does this:
# This rule has no dependencies: we don't need to update $(DOMAIN).pot at
# every "make" invocation, only create it when it is missing.
# Only "make $(DOMAIN).pot-update" or "make dist" will force an update.
$(srcdir)/$(DOMAIN).pot:
$(MAKE) $(DOMAIN).pot-update
So since we're not using 'make dist', but instead 'make distclean', this doesn't actually appear to provide much advantage.
Bah, nevermind; the upstream gettextize does this:
# This rule has no dependencies: we don't need to update $(DOMAIN).pot at .pot-update" or "make dist" will force an update. /$(DOMAIN) .pot: .pot-update
# every "make" invocation, only create it when it is missing.
# Only "make $(DOMAIN)
$(srcdir)
$(MAKE) $(DOMAIN)
So since we're not using 'make dist', but instead 'make distclean', this doesn't actually appear to provide much advantage.