I think that you are missing how credibility and propaganda intertwine. The BBC gives you accurate reports on Indonesia and Chile to build credibility for when they want to lie to the benefit of Britain. Aljazeera give accurate reports on Boeing and Airbus to build credibility for when they want to lie to the benefit of Qatar. NPR give accurate reports on Angola and Bangladesh to build credibility for when they want to lie to the benefit of the USA.
One navigates an adversarial information environment by harvesting the free truth provided by those seeking to build credibility. Then one tries to avoid the flames when the same organisations burn their credibility to boost their funders and owners.
Encouraging conspiracy theories against one of the largest components of the US military industrial complex is precisely something Al Jazeera would be willing to risk losing credibility over. Not that they actually would, because there could never be sufficient evidence to disprove such a conspiracy.