I know you brought the context for WHY Rabbi Yitzchak was referred to as Hevaya
No, the gemara was not saying he was havaya.
At most it’s an analogy, and there is a way of reading the gemara which doesn’t even make that analogy, and according to the girsa of the ככר לאדן, you can’t even read the gemara as an analogy.
The Rebbe chose to read the gemara in a way which demonstrates the problematic idea he wished to espouse, but the gemara is in no way a proof.