It's difficult for anyone who doesn't work there to know, but I would guess based on what I know of how ranking decisions are made that you are mistaken. For example I worked there prior to the 2020 election and on Instagram there was no specific ranking rule of any kind related to keywords like that, and no intentional bias to push up one side or another in any way, outside of ads and government officials.
Your system, including subsystems, must have a filter for prohibited words, like n-word, f-word, etc. It's very easy to add another one. That could be another subsystem which very few people have access to. I suspect there are different subsystems. One strait with explanations, another shadow without. The second is something nobody talks about in public as it's difficult to explain, may be even illegal. The same way unwanted talks are being suppressed on other portals. Note, it's independent of recommendations system, which can be played with by assigning scores to words and phrases. Engineers who build those systems don't need to know how exactly they are used and what are the key words.
I can give you a first hand example. One big sh*ty bank didn't let me see my accounts if I refused to activate a debit card. After login they showed a message box, when I pressed 'cancel' they logged me out hoping I will 'click through' to get access. This way they didn't have to explain and could claim it was a bug. It lasted for months till I closed all accounts and they confirmed, but actually didn't do it. What I mean by this is don't expect big company to play nice.
