> is Rust the motivating factor behind linear types cropping up lately?
Philip Wadler wrote "Linear Types Can Change the World!" while he was working on Haskell back in 1990. I vaguely remember there were some mentions of possibly adding it a year or two before Rust was publicly announced, but it seemed like it was going to be far off at the time. I wouldn't be surprised if Rust contributed to a lot of the interest in it - Simon Peyton Jones did specifically say that he had "Rust Envy" for shipping something similar to linear types in one of his talks.
Linear Types can Change the World!: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.31.5...