Apple’s macOS Sierra is coming later this year, it will come with Safari 10 and there will be some change to the way Safari deal with Flash.
Even if you have flash installed on your Max, when you visit a website it will by default act like you do not have flash installed, this was confirmed by Apple’s software engineer, Ricky Mondello.
On websites that offer both Flash and HTML5 implementations of content, Safari users will now always experience the modern HTML5 implementation, delivering improved performance and battery life. This policy and its benefits apply equally to all websites; Safari has no built-in list of exceptions. If a website really does require a legacy plug-in, users can explicitly activate it on that website.
Whilst Apple has for a long time wanted to get rid of Flash, it is not just flash that will be treated like this in Safari 10. Other plugins like Silverlight and Java will be treated in a similar way.