I'm not disagreeing with Biggie throwing his share of sneaky shots (he also said "Who Shot Ya" in the Dead Presidents video when they talk about California), but I don't know what you are referring to in regards to the Get Money remix/Hit Em Up beat. It's a highly sampled bassline from Dennis Edwards, everyone from Rakim to Milli Vanilli to Geto Boys had already sampled it.
The single for Get Money was released in February 1996. Hit Em Up was recorded a couple months later (according to wiki) and released it in the summer of 96'. To diss Biggie/Junior Mafia, Tupac & the Outlawz decided to use the same Dennis Edwards bassline, change the lyrics from "Get Money" to "Take Money" and change the "Grab your t*ts when you see big Pop" Players Anthem line to "Grab your Glocks when you see Tupac"