I also run into this problem frequently. For me it happens when I swop plugins, typically when copying from another channel or when recalling presets. I usually end up copying the automation points from the old track to the new one that is associated with the parameter I want to control.
It does have some quirks though. It seems like there are different "types" of automation lane. For example, LPF info might look wrong if you paste it onto a fader automation lane, but it looks fine on a panning lane.
If it helps, try putting a single point of automation data at the very beginning of the project to make sure that the data is copied and pasted into the correct time. At least the points are in the right place, you'll just have to shift the whole thing up or down and do some scaling.
Point is, I totally agree, there should be an option to "Reassign automation to new parameter".
