I was waitlisted for the 2020 cohort, I never interviewed/got in..., I asked MW If I could resubmit my application for 2021 with updates which they did, to which I was waitlisted again, and just received an invite to interview last night.
"Make sure to click the 2019-2020 cycle hyperlink so that you are logged into the proper cycle, and then you will be able to search for our Summer 2021 app." you should be able to find the NA specific program doing this.
As far as I know you just wait to be invited for an interview, which may never happen. I was waitlisted last year, and then never heard anything after that waitlist email. Someone I worked with was also waitlisted but ended up getting an Interview ...