No, this isNOT a bug. The bottom ofthe documentation page for YYAXIS states that this function was introduced in release R2016a. It is not present and will not work in earlier releases.
It all depends on what you need to do. There are many new things in MATLAB R2020a that were not in R2017a. I would recommend looking at 2 links to help you decide.
Web page dedicated to highlithing the newest features
Best Answer