Version 2 of the API is now deprecated. We have no plans to deactivate it yet; it will continue to work the same way, it will still continue to receive and use our latest user-agent parsing code, and the database will remain available, but new API end points build will not be back-ported.
Please note that with the emergence of a series of new HTTP Headers: collectively known as "Client Hints", using Version 2 and relying only on User Agent strings is no longer enough to properly detect a browsing set up. Version 3 of the API addresses this issue. You can continue to use Version 2 but you will not get the best browser detection any more.