As slack user “otto42” pointed out:
… no, we won’t publish a plugin that isn’t public. You submit the plugin, we review it, you fix the problems, we review it again, and so on until it’s suitable for public publishing on the site.
As for plugin-update-code, if your plugin has its own update code, then it is very likely to be rejected in the first place. We have update code for the directory, you don’t get to use your own. If you mean code to process changes in versions, then we can tell you how to do that correctly before the plugin goes into the directory.
So, in short, there is no need for you to “test the directory” process, because we won’t put it in the directory until we’re sure it’ll work properly in the first place.
@jdembowski Thank You for Your assistance. Sorry for not posting to the right sub-forum. I will write them on slack, and post an answer here, if I get any.
Cheers!