How long will you guys support 1Password 7 on Mac?

XIII - you're right that's what Michael Fey (aka mrrooni around these parts) said in that blog post, and it is accurate. But "maintenance mode" isn't quite the same thing as what happens to old versions when a new full version is officially released. For example, the release record for 1Password 7 for Mac since April 1, 2020, has been as follows:

• May 5, 2020: https://app-updates.agilebits.com/product_history/OPM7#v70500003
• July 7, 2020: https://app-updates.agilebits.com/product_history/OPM7#v70600005
• November 16, 2020: https://app-updates.agilebits.com/product_history/OPM7#v70700015
• March 9, 2021: https://app-updates.agilebits.com/product_history/OPM7#v70800000
• April 14, 2021: https://app-updates.agilebits.com/product_history/OPM7#v70801003
• May 10, 2021: https://app-updates.agilebits.com/product_history/OPM7#v70802002
• May 18, 2021: https://app-updates.agilebits.com/product_history/OPM7#v70803004
• May 25, 2021: https://app-updates.agilebits.com/product_history/OPM7#v70804003
  
• June 1, 2021: https://app-updates.agilebits.com/product_history/OPM7#v70805001
• June 15, 2021: https://app-updates.agilebits.com/product_history/OPM7#v70806001
• August 10, 2021: https://app-updates.agilebits.com/product_history/OPM7#v70807004

Granted, those last few were incremental releases focusing on feature parity with the upcoming version 8, but that's four point-releases and seven incremental updates to 1Password 7 for Mac since April of 2020.

By contrast, the final update of 1Password 6 for Mac was on May 18, 2018 - the same day 1Password 7 for Mac was released - and there have been https://app-updates.agilebits.com/product_history/OPM4 since that time. Should there be critical security issues discovered, updates will be issued to legacy versions, but development work on 1Password 7 for Mac did not stop in April of 2020. It is likely to once 1Password 8 for Mac is released, just as past versions have when new versions are released.

To be clear, those older versions will still work on the combination of operating system and browser(s) for which they were originally designed. If you still have a Mac running Snow Leopard and a concurrent version of Safari or other browser, for example, you can fire up 1Password 3 for Mac on it, and expect it to work mostly as it did back then. I say "mostly," because even preserved in amber like that, the Dropbox API that allowed for sync in 1Password 3 for Mac was deprecated by Dropbox years ago, so even if you did have such a Mac somewhere in your house, Dropbox sync in 1Password 3 for Mac would not work due to the passing of time and change in underlying systems.

And if, like most people, you continue to upgrade your hardware, version of macOS, and your browser(s), 1Password 7 for Mac will continue to work with both 1password.com accounts and standalone vaults and advanced syncing...but there will be increasing incompatibilities over time as technologies used in those areas continue to develop and older code is retired.