Apple will end 32bit support, meaning Safari should have to change.
Personally, I don't use the pdf thing, if I have to use Safari I just use a preset created within another application (Chrome). As long as you choose the preset and don't go into the Printer Features section after doing it, all the options should work.
And since it is a web browser, it isn't like anything advanced will be needed, you certainly won't be making a Book out of a web page.