Thanks, bro! But I don't know if this specifically was exactly the case. It seems to me that João balked away from the conflict with the Cortes, but that was his personal decision, he was never a man of conflict, and it was never his intention to stay in Brazil forever. Nonetheless, it doesn't seem like they could so easily get him by force had he chosen to resist, to say the least, considering the Brazilian elites insisted on having Pedro as Prince Regent as a guarantee against the Cortes even before the recolonization attempt was fully enacted. I would never say he was powerless in Brazil, he just felt weak in comparison to the metropole, but I don't think they would try to do like they did with Pedro during the Dia do Fico. Pedro was, at the eyes of the Divisão Auxiliadora (Rio's Garrison) a brat who was defying not only the Cortes and the metropole but his own father the King, who had already returned, so they tried to capture and force him back. But I don't see them doing this with João or even with Miguel, kings in their own right, specially under the declared intention of going back to Portugal, if only without a constitution.
And even if this were the case, the death of Pedro at the hands of the liberal pernambucans would probably explain a general change in alignment at least in Brazil, considering this did motivate João to crack down on the Brazilian liberals ITTL. The death of a prince heir at the hands of revolutionaries would affect even moderate constitutional monarchist liberals, and would surely serve to sway the heads of the garrisons.