OBC CDs are a pretty low priority when it comes to production schedules so delays may become the rule. However, I don't think physical CDs for cast albums will be eliminated any time soon. If anything the market is expanding -- more obscure off-Broadway and off-off-Broadway scores are being released on CD than ever before. In addition the release of OBCR on LP is actually booming.
The biggest change I've seen over the last 10--20 years is that titles are no longer routinely kept in inventory unless they are huge sellers like Hamilton. If you want the CD, it's best to get it as soon as it's released.