Answer
The reason he said that is because there is a tradition at the Kumbh Mela: if you become attached to an Akhara, you may join their procession. Kumbh begins with the grand and prestigious procession of all the akharas proceeding first for the sacred dip.
What he meant was that from the next Kumbh onward, A. C. Bhaktivedanta Swami Prabhupada would have a place in that procession. Since we would be joining with them, Prabhupada would be recognized there, and devotees would also participate in one of the most traditional processions, much ahead of many others. So his statement was specifically in the context of the procession and ceremonial participation.
It does not mean some deeper institutional merger or that everyone is unaware of philosophical distinctions. They clearly know who we are and what our position is.
When it comes to spiritual philosophy, there are distinctions. But when it comes to respectful social dealings and preaching within this world, we honor them as sincere spiritual practitioners. In fact, many of these akharas are not strictly aligned with classical impersonal interpretations and have developed distinct traditions over centuries.
They may be deeply devoted in their own worship, just as we are intensely devoted to Krishna. The philosophical differences remain, but those differences are not the main point in such social or ceremonial interactions.
Our connection is not one of doctrinal absorption into their system. It is simply a respectful association for specific occasions like Kumbh, where Prabhupada would be given due recognition and representation.
And from the preaching perspective, if they glorify Prabhupada, that itself is a tremendous spiritual benefit for them. To glorify a pure devotee is among the greatest blessings one can receive.
The whole world should glorify Prabhupada. If even great scientists, leaders, or other respected personalities glorify him, that brings them immense spiritual benefit. That is how such appreciation should be understood — as a victory for preaching and as auspiciousness for all involved.