Question regarding CHIPS

[anime2u]

I have a site currently using the logic of creating cookie using wildcard, eg web domain www.xyz.com, cookie host .xyz.com. the reason is to support other hosted sites/url/servers sit on abc.xyz.com or reporting.xyz.com. currently .xyz.com cookies are accepted. Looking at CHIPS examples, I found it is talking about cross-site between a.b.com and c.b.com. So I am wondering the current practice of generating cookie with .xyz.com host, will be impacted by coming change? do I need to add iframe for each needed subdomains to allow everything to continue working as is? thanks