If I migrate my Nameservers over to Cloudflare, do they become the source of authority for all changes that pertain to my the domain in question? Is there anyway around this?
What do you mean by “migrate nameservers”? You wouldnt migrate your existing nameservers but you would assign the two nameservers given to you by Cloudflare to your domain.
And yes, they will become the authoritative nameservers in this case and there is no way around this, unless you go for the Enterprise or IIRC Business plan where you could configure a CNAME setup.