To me, it is not. If the internet or anything else goes down you lose all access. You are not hosting your services, so claiming to be SELF-hosting is not really accurate.

Furthermore, in the phylosophical aspect, you depend on a private company for all your infrastructure and are not doing anything against the centralization of the internet. To me, this is one of the core reasons I self-host. Maybe we need to make new terms for this, but allowing anything under the corporate cloud umbrella to be called SELF-hosting seems bad to me.