Considering that's a low end iPad I wouldn't expect it to support all the Pro features, yes I wouldn't be surprised if iOS 11 leveraged some of that 4Gb ram and the ones with 2Gb wouldn't be able to do some fancy new things
Ok, well if that's your train of thought then I'd recommend a Surface Pro book with a core I7 loaded to the gills in specs. The iPad pro 12 incher is the only 4gb device. It's iOS, so it's not even a real fully fledged Operating System. No developer is going to write an app that only works on one, or two iOS devices that has more than 2 gigs of ram when the majority still run on 1. We're getting into spec fantasy land here. So I say if you're a hardware spec guy, go with a real CPU and OS in a surface book, or get an iPad pro and don't worry about memory, or CPU power. Either way both will last a super long time.