Short answer: Pretty much (I'd use the word "most" rather than "any.")
Longer answer/How the pieces fit together:
Your groov 2.0 (OPC-UA client) connects to the OPC-UA server. FYI - many of the existing OPC-UA servers on the market have KEPServerEx under the hood. The OPC-UA server needs to include a driver to the PLC or other hardware you'd like to connect to.
Note here that the -UA is significant (vs. -DA, the original "OPC"). The KEPServerEX has a -DA driver available too. So if your "third-party... SCADA" is also an OPC client, either -DA or -UA, then you could connect it to your groov client via that same server.
KEPServer even includes an ODBC driver for connecting to databases. And there's some memory/variables/registers included as part of the server where you could store some data to be shared between clients, if you'd like.
The possible combinations are nearly limitless!
Hope that helps.