Hi Jason,
Thanks for your interest in Typekit. There won't be any interruption to the font serving for your websites if an employee's Creative Cloud subscription ends. Removing a user from your Creative Cloud team subscription does not automatically delete the web font kits from Typekit; you would need to sign in to the Typekit website and chose to delete the fonts as well.
Typekit Support will be able to help you to transfer those kits to another employee who has Creative Cloud or, if that isn't an option for any reason, convert the Typekit account to a standalone subscription. (The standalone Typekit plan would be billed separately from Creative Cloud; current subscription prices are available on our website: https://typekit.com/plans.)
In either case, email us at support@typekit.com for more information when (if) you need to make these changes. You can also feel free to get in touch at that email with any other questions you have on using Typekit.
I hope that this helps! Best,
-- liz