I contacted CZ-USA via email today (11/13/2021). They said that due to the current C-word situation, they are not focusing on parts, just firearms.
The front and rear sights have NOT been discontinued. They will receive more metal factory sights when the firearms insanity slows. But they (or any one else) do not know when that may happen.
He suggested signing up for the "Subscribe to back in stock notification" at the webstore to know when the front sights are back in stock.
Hope this info was useful.