Just testing out various programs in Windows 10 and I have found these results from trying to playback Atrac3plus. The .oma files were encoded in 352kbps protected and not protected.
Windows Media Player Classic: Protected YES Unprotected YES
Vegas Pro 15: Protected YES Unprotected YES
Audacity with FFmpeg installed: Protected YES Unprotected YES
Foobar2000: Protected NO Unprotected NO (heard it works with a plugin, havent tried)
VLC (heard it works like mpc but havent tried.)
Winamp 5: Protected NO Unprotected NO
Chrome: doesnt try to open it
Steam: Doesnt pick up the file
I'll add more programs to this as I do more testing. Might do Atrac1 292kbps if someone can show me how to record to that in sonicstage4.3. Probably nobody bothers with Atrac3 anymore do they?