These are just comments posted on ProPakistani, so its validity is unconfirmed.
There is no mention of overseas Pakistanis for remittances. Here is what it says in ordinance.
Income Tax Ordinance
111. Unexplained income or assets.
(1) Where —
(a) any amount is credited in a person’s books of account;
(b) a person has made any investment or is the owner of any money or valuable article;
(c) a person has incurred any expenditure2[; or]
(d) any person has concealed income or furnished inaccurate particulars of income including...
...
(4) Sub-section (1) does not apply,—
(a) to any amount of foreign exchange remitted from outside Pakistan through normal banking channels 4[not exceeding 5[five] million Rupees in a tax year] that is encashed into rupees by a scheduled bank and a certificate from such bank is produced to that effect.
It doesn't say in Ordinance what happens above 5 million. But State bank says there is no tax above 5 million in this article, FBR will just ask for source of income.
So, by law, if a Youtuber has Proceed Realization Certificates for foreign remittances, there is no income tax.