It seems that you have a misreading of MN1.
"ordinary person perceives nibbana as nibbana. But conceives things about nibbana. Can read it in MN 1"
And you concludes a
"notion of an ordinary person is able to see nibbana while not being a sekkha(learner)" !
I don't know what is your intention while quoting a missing part of MN1, because it concerns an "uninstructed
run-of-the-mill person" or an "uninstructed ordinary person" (and the missing part is) who has no regard for noble ones, is not well-versed or disciplined in their Dhamma; who has no regard for people of integrity, is not well-versed or disciplined in their Dhamma.
This worldling one imagines what is Nibbana, he speculates about Nibbana, and so he thinks about Nibbana through mental conceptions and proliferations.
So if you go to a retreat and follow instructions are you a learner now or you become a learner after seeing nibbana?
Now the one who hears, learns the Buddha teachings, then practices according to the Buddha Dhamma, he is an "instructed ordinary person", he is a hearer (Sāvaka)
With practice, he sees for the first time Nibbana by direct knowledge. and he becomes a Stream winner Sotāpana (magga, phala). The next stages are the Once-returner Sakadāgāmi (magga,phala); the Non-returner Sakadāgāmi (magga,phala), the Holy One Arahatta-magga.
A noble one who is at the one of these 7 stages is called a Sekha (a learner
- because he well assimilates what is learned from the Buddha teachings).
And finally the one possessed of the 4th fruition, or Arahatta-phala, is called "Asekha" (no more learner
because he has finished the task, laid down the burden, attained the true goal, destroyed the fetters of becoming, and is released through right knowledge....)
that's my 2 cents....