How Can the Tablīghī Sect Convey True Islām to Others?

Shaikh Fawāz al-Madkhalī said:

The Tablīghī sect haven’t [even] conveyed the true religion of Islām to themselves, so how [could] they convey [it] to other than themselves?!!

Source: twitter.com/fzmhm12121. 9 Jul 17. 1:43 pm.