Source Japanese quote and English Google translation for reference:

I think solutions that combine both conditions and don't treat them as one or the other are more likely to come close to the final resolution, but it will take hindsight, and dare I say humility, from us to reconsider some of our initial positions, particularly "AC not being a sequel to 7R".

Now in the interest of balance: I think the FF7 Remake narrative changes can both serve a purpose AND not undo Advent Children as a direct sequel, and we don't even have to go too wild in terms of interpreting the trilogy for that to work.