I don't know if it is your case.
Before the change I have tried (v5.16)

csound -odac diskin.csd
...
WARNING: diskin: opened 'beats.wav':
        44100 Hz, 1 channel(s), 88200 sample frames

WARNING: bufsize 4096
...

and we can remove these messages with

csound -odac --m-warnings=0 diskin.csd
# of course -m0 also works

But with diskin2

csound -odac diskin2.csd
...
diskin2: opened 'beats.wav':
         44100 Hz, 1 channel(s), 88200 sample frames
...

csound -odac -m0 diskin2.csd
...
diskin2: opened 'beats.wav':
         44100 Hz, 1 channel(s), 88200 sample frames
...

After the change in git,

csound -odac --m-warnings=0 diskin2.csd     # or -m0 etc

the "diskin2: opened ..." message has disappeared.

tito