You need not worry that you will be affected by this move to the Annual Service Plan.
If you are already using previously-purchased plugins from us, they will continue to work as they have always done. While these legacy plugins will no longer be updated, and may not be compatible with future operating system or Adobe Illustrator releases, their licenses remain valid and available for Adobe Illustrator CS6 to CC2019 on both Windows 7 / 8.1 / 10 and macOS 10.10 through 10.14.
You should have kept a record of your license keys for future reinstallation with the older Unified Installer Installation Method. If you are experiencing any issues locating your license keys, please contact us quoting any known email addresses to which your plugin(s) are currently registered.