At the moment it's a bit difficult to say, as Samsung hasn't really made an official statement. The only thing I have seen is that Samsung has postponed the release of the Odyssey G9 from the end of July to mid-August on their website.
My guess is that the first deliveries will take place at the beginning of August and that availability will increase in the course of the month.

https://www.computerbase.de/2020-07...

After living with the problems of the G9 for almost 2 years, I sent the monitor in for service at the beginning of September. The LCD panel was replaced and all problems have disappeared, G-Sync and 240Hz work perfectly, no noise when heating up and cooling down, no flickering and artefacts in office use. I can only recommend sending it straight to service and not waiting two years like I did.

I received a model from Digitec on Thursday with the same quality defect. That's a real bummer. Hopefully Samsung will come to terms with the price.

The problem also (still) affects the monitors that have now been delivered.

In the meantime, the monitor has been shipped and should arrive today.

After the deadline was not met twice, the customer service told me that they would know more "at the end of the week".
As of today, the delivery date is "end of August"...
Great information policy (also from Samsung)...