I think the reason that it is a real change and not just an aesthetic change is because of that .8 multiplier. (Thanks to Hockeyfan for being the first to explain this to me, post 8 above.)
If you did a second solo quad and it was scored as a (failed)
combo, you would still get full value (9.0) for the quad as the first jump of a combo.
But if it is scored as a failed
sequence, then, because of the .8 multiplier applied to all jumps of a sequence, you only get 7.2 points for the quad.
Now that I understand it, I think the change is a good one.
MM