I'll post up the exact reply so I'm not putting words in Ableton's mouth:
Hi there Joshua,
Thanks for your email.
Yes, if you upgrade to Live 9 Standard, all of your existing instruments will be carried forward in the upgrade, and you will be able to download the updated versions via your user account at Ableton.com.
To use Max for Live with Live 9, you will need Max for Live 6.1, which will be made available to you on your user account page after the release.
Since you already hold a Max for Live license, the only extra content you'd get would be the Orchestral Instruments Collection.
If you upgrade to Live 9 Standard, you'd still officially be a Standard user, but your upgrade pricing to Suite would be considerably reduced.
For more information, please refer to our Live 9 FAQs:
Should you have any further questions, please do not hesitate to let us know. In the meantime, feel free to browse our Knowledge Base:
All the best,