> I don't believe any recommendation from the Constituent Assembly was received to the best of my knowledge
The Constituent Assembly provided its recommendation in the 1950s [1]. (I think this is where Article 35A came from.) The Assembly doesn't appear to have convened since 1954. It thus makes sense to interpret the recommendation requirement in 370(3) as a prohibition on the Indian President cancelling Article 370 before the Assembly had a chance to make its circa 1954 recommendations.
(Surprisingly, one of those changes was not a mutuality requirement on termination of the Article.)
But I don't believe any recommendation from the Constituent Assembly was received to the best of my knowledge.