This means that you can use whatever email provider you want. You appear to be using Microsoft 365 purchased through GoDaddy. It sounds like you might be considering moving your domain registration to Cloudflare and are concerned about your GoDaddy Microsoft 365 no longer being available if you move the domain away from GoDaddy registrar.
You may want to consult with a Microsoft CSP partner to evaluate whether to migrate to a new Microsoft 365 tenant or defederate your existing GoDaddy Microsoft 365 tenant. Both are valid options that will probably be easier to accomplish by working with someone who has done them before.
As @Laudian indicated, this falls outside of services that Cloudflare offers and is something you will want to pursue with your own trusted consultant.