From the days of John the Baptist until now, the kingdom of heaven has been subjected to violence, and violent people have been raiding it.
Luke 16:16:
Law and the Prophets were proclaimed until John. Since that time, the good news of the kingdom of God is being preached, and everyone is forcing their way into it.
These two views are clearly rival views.
Matthew 11:12 doesn't like what is happening in the time after John the Baptist: the Christ of the Marcionite heresy is giving a bad name to the Christian Gospel.
Luke 16:16 does like what is happening after John the Baptist, but with a warning: even if the end of the Law and prophets is hailed positively, between who wants to enter in the kingdom not always there are good people. A possibility is that also this absence of moral distinction among the new entries in the kingdom is hailed positively: even the Sodomites and Pharaon and Amalek were accepted by the Good God according to Marcion.