Presets can be migrated. Migrate presets in Photoshop CC
Extensions are a special case. 2015 release of Photoshop CC: FAQ They have to be reinstalled and you have to check with the maker for updates. Some plugins can simply be moved to your new plugins folder. Look under the section under Extensions in this help doc.
There is a very good reason these things are not automatically migrated: they often cause problems in a new PS version. PS developers can't accommodate for third-party plugins.
The recommended procedure is to check with the plugin vendor if they have an updated version, or whether the old version is confirmed to work without problems.
Then install them again in the new PS version.
EDIT: cross-post there, Gene, as you can see I'm taking the careful approach
Don't mind at all, Dag. Your input is valued here.
Thank you both for your advice. I was afraid this was the case. I guess I will update my home laptop first in case any of them (mostly Topaz Lab & Alien Skin filters) are no longer compatible.
It is always a double edged sword to have these major updates. It is great to have the new awesome features but a pain to have to learn where everything is found, named, looks like, and acts after the update. Then to add the need to reinstall those go-to filters etc.
It means that I need to find a non-busy time to learn a new workflow. Especially when all the Adobe CC programs come out with a major upgrade at the same time. And there is always something that I use regularly that seems to just disappear.
In this case you have the option keep and run your previous versions. Use them for time sensitive projects or in case 2017 cross threads with something.
Oh, that's great. I thought we lost that option when we went to the CC version.