My guess is that cron-apt will actually run with multiple cron daemons, so making cron a dependency would break that.
cron-apt Depends: apt Recommends: liblockfile1 Recommends: <mail-transport-agent> courier-mta esmtp-run exim4-daemon-light msmtp-mta nullmailer opensmtpd sendmail-bin ssmtp dma exim4-daemon-heavy postfix |Recommends: cron Recommends: <cron-daemon> bcron cronie systemd-cron cron
It would be nice if someone could tell us for certain though.
My guess is that cron-apt will actually run with multiple cron daemons, so making cron a dependency would break that.
cron-apt -agent> daemon- light daemon- heavy
Depends: apt
Recommends: liblockfile1
Recommends: <mail-transport
courier-mta
esmtp-run
exim4-
msmtp-mta
nullmailer
opensmtpd
sendmail-bin
ssmtp
dma
exim4-
postfix
|Recommends: cron
Recommends: <cron-daemon>
bcron
cronie
systemd-cron
cron
It would be nice if someone could tell us for certain though.