Hey
gmat7m. Just a fellow applicant here, but I think you should submit a new goals essay as well as the letter. Ross' app is exceptionally to the point, so I would just see it as an extra opportunity to provide more info and get your personal brand across. I would do the goals essay first and include the leadership aspect you think was missing from last year. Your revised essay will likely present a clearer narrative with the inclusion than your old essay + the update in the applicant letter combined separately. Make it easier to make your best case to the adcoms this year given what you took from your application last year. The reapplicant letter you might focus more on achievement updates rather than the goals updates, but I'm guessing you also can elaborate on your goals a bit more and take advantage of the extra space (within reason). Perhaps you can demonstrate your ability to reflect and be self-aware in speaking on how your more refined goals in your essay are different than what you shared before. There might even be actions you took/achievements already that came out of that reflection. If that did happen I think those are things you'd want to include in the reapplicant letter or some other aspect that doesn't fit with the essay prompt. Probably to avoid annoying the adcoms you'll want to mention something that doesn't match as easily with the essay prompt or is particular to reflection from last year's essay rather than just adding things that couldn't fit in the word count of the main essay (IMO). Not sure if you're doing GMAT re-take and how many other schools you are applying to, but with almost a month left I bet it will be a good use of time.
Also it's not in your control right now whether they'll look at your original essay or not, but without submitting a new essay it's probably much more likely they'll be taking a very close look at the one from last year.
Sort of unrelated I was listening to the Preparing For Round 1 webinar recording last night and from Soojin's reflections on the new short answers it sounds like they are pretty excited to see applicant's responses and I think there was a comment about how they did them deliberately because they think this will help the adcoms learn who you are as a person more easily. You might already be planning to do those new essays as well, but if not, might think about doing those as well if you have the time. To your question about whether not doing them would show a lack of interest, I think the effort you put in last year and the resiliency in coming back and applying again I think would weigh that out, but it can't hurt to provide more info and show extra effort just in case.