Audax rides

That's fucking dumb. Why would they remove DIYs?

Probably to discourage unnecessary travel, and the fact that doing a 200km Audax isn't "necessary" to maintain fitness. With the current Government recommendations you're free to go out and do whatever you like on a bike in the name of exercise (keeping social distancing in mind).

If you need to do a 200km ride to maintain your fitness then go out and do it, but you don't "need" the Audax bit of it. If AUK kept DIYs/awards going then that might be seen as encouring people to do rides they wouldn't have given the current situation.

Also, are they planning on communicating this news to us?

The previous official announcement (13th) was emailed to all members a few days after it appeared on the AUK forum, I assume they'll do the same with this one.