You can thank Southwest for that.
They had Boeing install "INOP" labelled metal plates on the MCP to prevent VNAV and A/T from being used on their 737NG fleet up to 2009.
When they opted to take advantage of RNP approaches, they had to re-train crews and enabled A/T and VNAV. This alone achieved millions of $$$ in savings within the first month.
Still, they want to keep commonality for good reason ($$$) and have a lot of say in the MAX development. Since the -200 fleet, the goal has been to keep the next generation of 737 derivative as close as possible to the previous one.