I’m updating the Java SDK version used by our application and noticed V1Transactions.Payments is deprecated in GitHub. However, the V1 Migration page shows TBD for deprecated and retirement so it’s a bit confusing.
Can you give more clarity on this? If it’s deprecated, is there an update on the retirement timeline by any chance?
Currently, you are correct. The Transactions API is deprecated. However the retirement date still hasn’t been set. These endpoints are also removed from API version 10/20 and newer (“removed”, not retired). This applies to SDKs also. We definitely recommend migrating to the Payments API as soon as possible. 
Thanks Bryan.
The Payments API is missing key datapoints that we pull such as Itemizations and tax data, so it’s not an option at this time.
The itemization and tax data is now in the Orders API. There isn’t any plan to support the itemization or tax data in the Payments API in the future so you will need to eventually migrate to use both the Payments API and the Orders API if you are wanting all the data.