That is a misstatement, India was meddling in the affairs of East Pakistan by the early to mid 60's via its various connections with Bengali dissidents who occupied positions of power. Then in Sri Lanka, and in Burma.. until this facade of self righteousness is ditched by Indians; neither side will ever sit down to talk. Each will think their high horse is better, and in my case.. leave me uninterested in any discussion.
Since you mention it,
@Oscar , this goes back to the 1930s. The Bengali dissidents that you mention were not a single-flavoured spread, they included leaders like Fazlul Haq, Suhrawardy, warts and all, Maulana Bhashani and Mujib as a bit player. The Agartala Conspiracy case was probably a case based on a genuine attempt at seeking political options outside Pakistan, but it was not necessarily an option for India. India was just a willing taxi hired for the ride.
You have to remember also that bureaucratic politics in India had a lot more to do with this than with interfering with Pakistan. In those days, there was no separate intelligence agency to handle matters outside the country; it was still the IB. Under B. N. Mallik, the reputation of the IB had taken a terrible beating in the period 1959 to 1962. There is reason to believe that Mallik's very poor interpretation of very diffuse data about the Chinese in Tibet contributed to the comprehensive nature of the military setback, and this was increasingly being hinted at in bureaucratic circles; Mallik was too powerful, almost an Edgar Hoover-like figure, in those days to be attacked directly. Under him, and under his successor, there was an amount of quiet desperation to show something stunning and out of the box to regain the agency's reputation in the world of the Delhi bureaucracy. Eagerly drawing up chairs and sitting at the table with the disgruntled East Pakistanis was part of this.
You must also be aware of how little of substance was discussed and even lesser substance found expression in action.
Every word that you have written is correct. And then there is the context. The dates show us something interesting. The conversations are supposed to have taken place in 1967 and the matter came to a head in 1968. If you look up what was happening, what the brave Shamsul Alam, the then Director of ISI in Bangladesh, was doing in the rest of his time, you will get very interesting results. If you wish, I will post you the references to the academic exegesis of the ISI involvement in the Mizo uprising. This was not a conversation; this was arming an entire rebellion, and forming camps, and pumping in money, and allowing the rebels to take shelter in the Chittagong Hills, until Bangladesh happened, after which the rebels first went to Burma, found it hideously primitive, and preferred to return to the few comforts that they had gathered with the ISI; they returned to Bangladesh, which had by then got rid of Mujib in a time-hallowed manner, and welcomed them back.
Working out who made the first move is not as straightforward as we might think. An history of this region's intelligence by-play would make very curious reading, but in a role of specific advocacy, I would like to argue that we followed suit, never using trumps.