Whether or not you think gradual escalation prevented nuclear escalation, it's pretty much done now. Given the US policy of not announcing shipments until they've been used in the field, I bet that ATACMS is currently en route to Ukraine. Storm Shadow and ATACMS are roughly equivalent and they already have Storm Shadow.
F-16 and ATACMS were pretty much the last things on the Ukraine wish list, and they're now (probably) getting both.