In an email from Workflow support sent to a user of the app, and discussed on the Accidental Tech Podcast (via iGeneration), the company has confirmed that there are "no further planned updates for Workflow," but it will continue to support the app's current functionality and has no intention to fully abandon it.
"But just so you know, we have no further planned updates for Workflow. That being said we are continuing to support Workflow's current functionality and have no plans to end support, so let me know if you run across any bugs or crashes."Following the acquisition, Apple made Workflow free to download on the App Store and reimbursed customers who had recently paid for the app. Certain features were also removed from the app after Apple bought it, including workflow functionality that involved Google Chrome, Pocket, LINE, Telegram, and Uber.
Apple is predicted to include Workflow directly into iOS in the future, at which time the current Workflow app will likely be removed from the App Store. As such, the app is now sitting in a sort of limbo stage between its recent acquisition -- where Apple also received Workflow team members Ari Weinstein, Conrad Kramer, and Nick Frey -- and a future integration in iOS, perhaps iOS 11 this fall.