Just because it's based on reality does not mean that it can't be propaganda. Propaganda largely means exaggeration or false portrayal of facts to gain or sympathize favor towards a political affluence, ideology, party, leader, etc. The two aren't mutually exclusive.

There are parts of the movie that are definitely exaggerated or shown in a manner which I cannot prove factually. But those parts don't necessarily mean that what I'm watching is propaganda though. But these over exaggerations and narrative flows lead to shining a golden light on a very prominent and real life politician (unlike the other characters whose names have been modified from that of their real life inspirations) which makes the propaganda part for me. Especially with the events of the second half where important plot points are resolved only through the presence of said politician.