Public Subdomain restrictions?

I have a domain that I’ve purchased and would like to create Subdomains for myself. But I am wondering if I make subdomains for myself for a domain now, is it not possible to make it public on sites like ENSnow afterwards where other people can search for their own subdomains on their own?

ENSNow uses the subdomain registrar contract, which will respect (Eg, not allow registering) any subdomains you’ve already created for yoursefl.