TCF requires replacing the "gdprApplies" param.

AMP doesn't support that variable. The closest is the consentRequired field.
consentRequired doesn't work well because its value can be true when another regulations applies. Since AMP decided to support IAB TCF, I propose we introduce a new field to the CMP endpoint response "gdprApplies". The value will be stored along with the consent string and passed to ad vendors.

{
  "consentRequired": {boolean}
  "consentStateValue": {?enum} [default: null]
  "consentString": {?string} [default: null]
  "expireCache": {boolean} [default: false]
  "gdprApplies": {boolean} [default to consentRequired value]
}

Note: AMP will use the "consentRequired" value if the "gdprApplies" is not defined.

Important Notice:
AMP reduces the delay by always respecting the localStored value, and only updates it for the next user visit. That will apply to the "gdprApplies" value as well.