Sitemaps after transferring to new domain

I just transferred an Italian domain to a new one:
mydomain.it (Italian content) -> mydomain.com/it
mydomain.com (English content) -> mydomain.com , which already existed

[ I have done all the redirects, so that all the previous content is individually redirected to the correct url on the .com site. I will keep the wordpress installation (with no content) up for a few months, with all the individual redirects active. After that, I will simply redirect the whole top level domain to the new site. ]

My question is about the sitemaps.

I had a Yoast-generated sitemap on the old site. What should this sitemap now contain? Or should I simply delete it and let the redirects do their work?