It can mean either. I had mine done a few months back and the part number is the same. It is believed that they did revise the reservoir at some point late last year early this year but I cannot confirm that.So I've had mine replaced once already. Does this coverage usually mean they fixed the problem and now have a new part to replace the old one or they're just offering to keep replacing it until the special coverage ends?
Diesel its worth a shot, but it is a long stretch due to your milage.