Conjugation of 'to establish' with 'the plan' does not seems natural. Use of 'to make/ to create' would be better, I think.
We will look into this matter, but the point here is to teach the word 'establish'.
There are two common English uses of the word "establish": (a) To establish an institution (स्थापना करना) and (2) to establish (prove/confirm) a fact (तय करना, perhaps). It might be better to teach the word "establishment" using one of those uses...
Thanks, Vaidya ji :)
Will Hindi Duolingo Team accept this suggestion to teach the word "establish" in proper context. :)