The fuss was not about acknowledging Jesus was the servant of the Father or that submission is Christ-like, or even saying that women should submit to men. It was about the claim of ontological subordination within the Trinity. They were indeed clearly saying that the Son was less than the Father when it came to several divine attributes. It was heretical for lots of technical reasons people can go read about if they feel like it. I realize that this is an intramural sport between professional theologians and not very grounded in things the average Christian cares about.
Grudem and company wanted to argue that women are ontologically subordinate to men. It isn’t a role they’ve been given, it’s core to their identity. Their submission to men is not just a righteous response to a gender-specific calling that they offer by their own free will because they are commanded to by God, nor is their subordination some effect of the fall or curse. Rather female subordination to males was designed into their nature at Creation and will endure for all eternity, even in heaven.
[ETA: Here is a short explanation of the difference between the Economic Trinity and the Ontological Trinity as it relates to the debate by one of the conservative, Reformed theologians who agreed eternal subordination of the Son was heretical.}