It's not a matter of "here is a list of requirements that no one knows about, and here is slight randomness/delay to obfuscate".
How much do you think it takes to pay an actual human from a poor country to come to work each day at 8am, create one github account after another, enter them in a database, and leave at 5pm?
If you want to "study" how github handles stars because there is legitimate financial incentive for you in it, for $100 a day you can pay 10 or 20 of those people to create few thousands accounts a day. Do it few times a month, and throw these accounts in an automated system that creates random repos, pushes a few commits here and there, etc. Also "introduce some slight randomness or delay to obfuscate these events". Do some A/B testing to figure how the 300k accounts under your control affect a repo star system, then advertise a "GitHub stars service" "$0.50 per guaranteed star on Github". Your average VC funded startup could get 10k stars for $5k.They probably give AWS 10 times that a month.
Once github changes their requirements, do more testing, figure out what the requirements now are, then you're back in the game. If people do it all the time to Spotify, YouTube, Google, Amazon, Reddit, and Twitter, why do you think GitHub would somehow crack that nut?