The change hasn't happened yet, but apparently a lot of cooking and cookbook subject headings will be changed in the near future or are still being considered for change: see the PDF on this.
The problem, as far as our local catalog goes, is that I am still performing all authority work manually. I could potentially make cooking and cookbook subject headings a special project for myself, but it would only be one of many special projects I've currently got going. Even if I made it a special project and, by hand, exported former "cookery" subject headings from OCLC and imported them into WorkFlows, there's still no guarantee I'd get everything (I'm still finding headings using the older "Vietnam Conflict", and I'm sure we've got more with "European War" instead of "World War", etc.). Plus, we have an unknown number of records with headings that, for some reason, aren't properly linked to their corresponding authority records - these would need to be "flipped" by hand.
This isn't really just a cookery/cooking problem - it's a general, "doing authority work completely by hand" problem. At this point, the best I can do is load new authority records, overlay any that have changed when a new bibliographic record brings those changes to my attention, and load records for unauthorized headings when I have time. I'd love to be able to go through the Library of Congress Weekly Lists and update an of our authority records that have been changed (or split, or merged, or deleted), but, at this point, that's just a nice dream.
Oh, and since this post deals with authority records, I'll just mention that from the beginning of June to today, the end of September, I've loaded 4,102 new authority records. We have a total of 243,981 authority records, period. Of these, 27,811 are provisional (in our system, that means that they're machine-generated and therefore contain nothing beyond the "authorized" form of the name or subject heading and the title of the work that was used to generate the record). A couple hundred thousand authority records may sound like a lot, but we still need many more. I'm working on it. I'm also working on overlaying as many of those provisional authority records as I can.
Ah, authority work, my eternal project...