Hello jerrys,
I've only just done what you've just done (opened ADR9 as part of DS365 for the first time). I didn't see any notification to activate codecs and have had no issues importing a sample set of audio clips which includes dozens of clips in a variety of formats & configurations.
If you weren't hallucinating and there was a notification at your end, I wouldn't be too concerned. As far as I'm aware, if codecs are installed on your system, active software will make use of them when necessary.
I'd carry on working with ADR9 &, if there is some related decoding or encoding issue report it here.
PIX
PIX YouTube channel