It is very delicate matter indeed. An Afghan soldier facing Taliban won't care who is providing CAS. He just needs it. On the other hand, Afghan government has elements loyal to Indians. They will do their utmost to discredit PAF with allegations like killing civilians, deliberately targeting Afghan soldiers etc.. Under any circumstances, PAF will receive targeting information from afghan agencies. It may not be as accurate or some elements may intentionally provide wrong Intel to cause civilian casualties. This will cause resentment in local populations against Pakistan and its military. These elements will use such incidents to create a propaganda storm.
Apparently Pak Military will be aware of this and is not likely to commit CAS for ANA.
You are watching too much CNN.
What experience / tech does the PAF have in providing CAS? PAF flying / bombing in Waziristan is very different from doing this in Afghanistan.