as the employers scheme is over and above the minimum for all workers, i would have thought they had the right to vary it as and when they wanted, as long as they are treating all employees equally
If they give you two months, they are setting a precedent that would actually change the whole scheme as they couldn't treat you more favourably that the next person to unfortunately be off sick.
In my mind this just means that the person who told you made a mistake,a nd now they are rectifying it by putting it back to normal