Bluetooth 5.2 or higher is the minimum but doesn’t guarantee compatibility either. Compatibility with LE Audio should be explicitly stated.
If you’re really keen, see Bluetooth dongle with Auracast support - FlooGoo FMA120. I don’t know if it supports older machines, but their support is good in my experience so you could always ask. Note it’s very new and support for the Oticon is only recent. Expect issues.
Finally, I’ve played around with LE Audio on a laptop and it didn’t play well at all with my mobile phone. It’s not (yet) like multipoint where you could be on your laptop but the phone picks up calls and automatically sends audio to your hearing aids. It was a major pain switching devices and often I just gave up. I don’t have a strong need to make it work personally.