Maybe this was the the people fighting against authoritarianism after being exposed to the external world and realizing how they'd been kept like pets by Mao?

the situation in china was such that after several years of liberal economic reforms, the social situation was rapidly deteriorating due to the smashing of the 'iron rice bowl', that is, the tenured jobs and generous welfare that had previously been provided by the state under mao. this made a lot of people very poor and miserable, but it also made a lot (albeit to a lesser degree) of people very rich and happy. also of note was the amount of political suppression going on at the time: the liberal reforms basically began not too long after the excesses of the highly traumatic (at least to the urbanized people who's opinions actually mattered) and highly political Great People's Cultural Revolution. political discourse was discouraged and ideology was highly de-emphasized in favor of 'non-political' matters of efficiency and production (sound familiar?). this set the stage for the rapid polarization of society into haves and have-nots, neither of which were terribly educated regarding the historical forces acting around them.

broadly speaking, there were two groups of protestors:

the first group were the students. of a generally bourgeois or otherwise privileged demographic, they were located mostly in and around the square in the duration of time (several months) leading up to the incident in june. they were more or less backed by the cia, or at least their leaders were, as evidenced by the speed at which they were evacuated during operation yellowbird. these guys were funded, ideologically motivated, and organized. their aim was to bring about even faster economic reformation (read: looting of the public sector) and along with it, privatization of government itself, mostly so that their families could benefit from leveraging their already privileged positions. these guys left the square when asked politely and were for sure way too rich to go around dying for a cause like chai ling so wanted.

the second group were the disaffected workers. proletarian in character and much larger in number, they were mostly ideologically illiterate and completely disorganized. primarily motivated by the hardships they were suffering under liberal reformation (unstable currency, uncertain job market, homelessness), they wanted a return to the maoist welfare state and reinstitution of the various benefits they had enjoyed therein. hilariously, they had tried to join the student movement in the previous months since general sentiment was not directed at policy but rather at the people in charge, but the students generally looked down on them as useless lumpen and excluded them from most events. these were the guys out and about lynching soldiers and getting into firefights and were the primary victims of the violence aside from the soldiers. it's unclear if they were provided with weapons or they just looted them off dead soldiers (though nobody entering the city was supposed to have weapons in the first place, that was a famous fuckup that resulted in one of the first violent clashes) but as with everything cia, it's best to remain healthily cynical.

Was China about to fall to college students?

china was about to fall to a bunch of disenfranchised workers disillusioned with the liberalism of 'the external world' and wanting a return to pethood under mao. the college students were there to be photogenic and try their hand at opportunism.