I'm pretty sure the percentage you're thinking of is if you are betting with the least volatile option, ie keno on classic or low with 10 numbers or plinko on lowest rows lowest difficulty.
that being said, no i think it's all made up. I think they definitely have the ability to decide when their billion dollar company needs to hit certain numbers to make investors happy. Also, I'm starting to hate how the provably fair system acts no matter where it's placed, certain quirks make me mad as fuck. like when you bet the last of your balance on keno high, sorry but you will not hit that last best 99/100 times.