Funny coming from churches that hold so many traditions, things Jesus did not say.
"On the contrary" is not an accurate translation of "menoun" (Μενοῦν) , which is moreaccurately rendered "truly indeed." The NKJV, which is a very high quality translation, based on very high quality manuscrip scholarship reflecting the best possible balance of textual criticism and liturgical tradition,
Don't we ignore the Mormon Bible for their interjection of their traditions into it?
and which is used for the NT portion of the Orthodox Study Bible, renders this passage as
"But He said, “More than that, blessed are those who hear the word of God and keep it!”
This is, clearly, in context, the right reading.
Only a tiny minority of Bible translations, excluding the KJV, the NIV, the ASB, the NASB, and others, render that passage as "on the contrary,"
Luke 11:28 needs the context of the previous verse and the backdrop of Jesus casting out a demon and being a great prophet that he should be so revered that even his mother should get "credit" for Jesus' existence. Sounds like this thread. As you point out, this is inline with the praise Mary received in Luke 1 from an angel.
27 And it happened, as He spoke these things, that a certain woman from the crowd raised her voice and said to Him, “Blessed is the womb that bore You, and the breasts which nursed You!”
28 But He said, “More than that, blessed are those who hear the word of God and keep it!”
BUT,
In verse 28 Jesus responds to the concept of praising Mary, his mother. He does not reinforce or assert this practice. It appears more as a rebuke than encouraging the behavior.
This is indicated by the words that introduce a contrast. Every translation conveys this contrast, whether by using: but he said, on the contrary or rather. Most translations include "but he said", even the NJKV.
Everyone should question when "but" follows praise, because it is used so often in life and we all know how it is used. As in:
I think your words are full of inspiration, but I think you need to fully research scripture to get the full meaning.
"But" introduces something in opposition, not something in support of the earlier statement. It doesn't necessarily negate the first statement, but it does introduce a statement that is not aligned with the first. It introduces an alternative idea.
This alternative idea is that even though Mary was blessed for a physical act, we are even more blessed for a spiritual act, to hear Jesus' words and follow them. And, this is completely in line with the many times Jesus rebuked the Jews for thinking they were blessed because of their heritage as opposed to their spiritual position.
and indeed, such a reading makes no sense at all, because it would directly contradict Luke 1.
St. Luke would not write, in chapter 1, the Theotokos praising God that "all generations will call me blessed," and then ten chapters later, have God basically say, "Nope, she was wrong, she is not blessed."
Indeed, there is no criticism of St. Mary anywhere in the Gospel of Luke, or indeed anywhere else in the Gospels.
As Matthew 11:11 asserts, any measure in this physical world of worldly acts and position is of lesser importance than even the least heavenly/spiritual act. It is not a contradiction to say Mary is blessed above all women for bearing Jesus, for that is an earthly/physical act and spiritual acts are so more important as Jesus says in Luke 11.