I already know the first balance nerf on those 2 civs:
Castles and tcs after a fest on douches and fc castle pushes decreased to 80%
They get back 45% of the gold instead of the 50%
The donjon will shoot one arrow less.
burgundian vineyards reduced to 1/3 of the total food converted to gold.
Scutage, they get 6 units per tc instead of 7.
And that would be all for the next 6 months.