Breaking changes in API?

Today, we use Trados 2019 and GroupShare 2017 (latest versions). We have a custom automation tool that connects to both and automates the creation of local projects, as well as the pretranslation using GroupShare TMs. Tomorrow, we want to migrate our stack to Trados 2021 and GroupShare 2020. Should we expect major changes in either API that would break our automation tool, or can we expect that our automation tool will continue to work with only minor updates?

FYI