Postscript: Friends,
Why would I want to delete my iCloud email address, when it could have been simply left unused (for the time being)?
Uneasily racking my brains, I'm unable to reconstitute the event cognitively but, emotionally, the desperation of that act has not been entirely forgotten. Whereas I assumed above that someone else hijacking my original address has been why even a new (suggested) address could not be created, it is starting to make more sense that it was the opposite that happened...
After successfully creating that address and accessing its mailbox in iCloud, I probably discovered that it already belonged to someone else. It's even likely that what drove me to attempt deletion, which I recall as not having been easy, was that messages started to arrive that were clearly not meant for me. New to this ecosystem and fearing that the owner might accuse me of having hijacked his address, I was perplexed & did not attempt to reach out to Apple support.
One might object that it would have been technically impossible for me to create an iCloud address that already belonged to someone else? But then, is it more technically feasible for someone else to have hijacked the (same) address I had created? The Apple advisors with whom I chatted this week were just as confounded and had to escalate the issue to an iCloud specialist, who was likewise unable to account for what exactly had happened as the result of my errant behavior...
In any case, I do hope Apple has closed any technical loopholes that might allow (re-) creating an already taken address.
Sunthar