expand on the spirit of the proposal to help disambiguate the future

The minutes were read and agreed upon by TPA, so I assume this
reflects the current will of the team. This will help in case there
are bits of the policy that are unclear in the future.

policy/tpa-rfc-7-root.md

@@ -61,6 +61,12 @@ on the servers they manage (and only those). It also tries to define a
 security policy for access tokens, as well as admission and revocation
 policies.
 
+In general, the spirit of the proposal is to bring more flexibility
+with what changes we allow on servers to the TPA team. We want to help
+teams host their servers with us but that also comes with the
+understanding that we need the capacity (in terms of staff and
+hardware resources) to do so as well.
+
 ## Scope
 
 This policy complements the [Tor Core Membership policy][] but