Admob Native Advanced ads are available for integration?

Its mentioned in Admob ads integration page that

The native express ad format is being discontinued. Starting October 23, 2017, you’ll no longer be able to create new native express ad units.
Existing native express ad units will stop serving ads on March 1, 2018.

Today is 24th and I can still see the option of NATIVE ads creation when click on NEW AD UNIT in admob.
Its is said that ADMOB NATIVE ADVANCED ads are still in Beta phase and can be available only via Account manager.
Does it mean that its NATIVE ADVANCED unit and available for usage?

Just a irrelevant stuff…

Go to your Admob Page
> Click on Monetize
> Select anyone of your Apps in Left hand side panel
> Click on “Settings” tab
> There is option Show no more than _____ impressions per user per _____ minutes

What will happen if this option is selected?

Does this option restricts the Number of impressions per user in specified time? For example if it is set to 10. It will not show 11th ad to the user within the specified time.
this option restricts the Number of impressions OF SAME AD per user in specified time and serve the different ad?