macOS Sierra: Smart Card Driver Extensions
macOS Sierra is not yet available. But Apple already provides documentation about what is new.
Note that Apple does not say what will happen in 10.13. I guess the message here is that support of tokend will be removed in 10.13.
tokend is deprecated since Mac OS X Lion (10.7 released in 2011. See "Mac OS X Lion and tokend"). tokend support may disappear in 2017 with 10.13. So that would be 6 years of deprecation.
Smart Card Driver
For example the page https://developer.apple.com/library/prerelease/content/releasenotes/MacOSX/WhatsNewInOSX/Articles/OSXv10.html talks about the Smart Card Driver Extensions that will replace tokend:Support for Smart Card Driver Extensions
You can now createNSExtension-based smart card drivers, allowing the contents of certain types of smart cards to be presented as part of the system keychain. This mechanism is intended to replace the deprecated Common Data Security Architecture, although for macOS 10.12, both architectures are supported.
The driver extensions are limited to read-only mode, so that it is not possible to alter the contents of a smart card using the standard keychain interface. For more information, see CryptoTokenKit Framework Reference.
Important points
"for macOS 10.12, both architectures are supported"
The good news is that both tokend and Smart Card Driver are supported in 10.12.Note that Apple does not say what will happen in 10.13. I guess the message here is that support of tokend will be removed in 10.13.
tokend is deprecated since Mac OS X Lion (10.7 released in 2011. See "Mac OS X Lion and tokend"). tokend support may disappear in 2017 with 10.13. So that would be 6 years of deprecation.