Why makes you say it is "premature"? Isn't it possible that they hit that limit because the project is a monolithic monster? Or because it uses libraries that waste those resources?

i'd argue the opposite.. i mean, i think you're referring to malloc when you cite premature optimisation, but this seems more of an issue of failing to optimise for the future or generalise beyond the initial needs of the developer

Is it still "premature optimization" if it bites after 12 years?