What's changed is instead of making low percentage strategic decisions, teams are using the available data and playing the percentages. Teams didn't utilize the shift until the early 2010's because they were ignorant and/or afraid the go against tradition and outside of particular situations with particular players, bunting, stealing and choking up with 2 strikes decreases your chance of success over the long term.
There's new strategies (with the backup math) on how to construct a lineup...there's change all over the place. IMO, they don't talk about the new strategies being implemented by MLB teams - instead opting to question why the manager didn't bunt in that situation, or put the runner in motion, etc. It misleads the casual fans into thinking the manager's an idiot.