I bet Jim can answer the question, I am giving an opinion on.

"Could the Sahara re-issue V9683 (CURRENTLY a Z6 CHIP) tomorrow?"

IMO, Yes, but I have grave doubts it could be an exact copy. The small key molds still exists. I think a CA company owns it. The problem is production methods have come into the 21st century and the small key mold would also have to come into the 21st century.

That said here is another problem.
A re-manfacturer could produce the inlay if he could find the exact blanks. There are 1,000's of blank small key chips for sale.

"Should a casino offer advance notice of release dates?"
IMO, yes.