why show this that create iphone and Android Apps
Nothing wrong with that.
You can create iOS apps with App Inventor if you join the beta program for building IPA files. Even if you don't, you can still test your apps with iOS.
So, you can create iOS apps with App Inventor.
Yes you are right. Prematurely advertising features that don't exist yet. Those who are in the beta program do not need this advertisement, they do not accept new people to the beta program, so I do not know who these advertisements are for.
This may attract people who want to create apps for ios, which is not yet possible for the general public, and unnecessary questions will begin ... they could at least add "soon".
are you provide mit app inventer beta program 
link
This post is from Oct. 2019 and I was already late at the time: