No, as part of our renaming, Hobby dynos and Hobby-Basic Postgres will be automatically changed to Basic plans. No action is required on your part. When they change to Basic plans, your app will restart. The impact is similar to any other user-initiated release.
Basic dynos aren't yet available. If you use hobby dynos in your app.json files, don't update them to basic until after November 28th, 2022. Even if you don't update your file after this date, any app.json files that use hobby dynos will provision basic dynos instead for the foreseeable future.
See our blog post and the Low-Cost Plans FAQ for more info related to our new plans.