Store metadata update

No, you can change the description whenever you want. Just don't change it so that it becomes inconsistent with the purpose of the app—that could get you in trouble. What you might have been thinking of are the screenshots, which are locked between app versions.

Thnks for your answer but my question is : is a change o the app name, screenshots or description considered as a new version of the app even if the app has technically not changed ?

Thanks again

Changing the app name and screenshots does not directly create a new version. Rather, the name and screenshots are locked until you explicitly create a new app version. The description you can change whenever you want; it's not locked.

OK so as i've seen today that apple will delete of the store apps that have not been updated for a while, my point is to create a new version of my app quickly and easily. Would changing the name or screenshots be enough to create/submit a new version ?

Actually, the new policy is more about ensuring continuing quality rather than just a recent release date. If you get contacted by Apple (which may or may not happen—it depends on whether or not your app works well on modern systems), you have 30 days to release a polished version that addresses those concerns. Creating a superficial new version isn't going to change that.

Have you looked at https://developer.apple.com/support/app-store-improvements/ yet?

The problem is that maybe about 80% of all apps on the store has their names longer than 50 characters. If Apple does not allow to change the name without updating the app, it will not be able to review all the updated apps. Does anyone know what may happen?

>Does anyone know what may happen?

80% of the apps in the store will be removed until updated. Pretty crafty of Apple to cut their business w/an axe, like that.

...not sure where you got that number, tho.

The name question might be a bit of a red herring. I don't know this for sure, but from reading the page it seems to me like apps wouldn't be removed just because of the name. If the app exhibits technical problems or seems outdated, then when you update the app you'd have to fix the name, but if everything's okay, then you can leave the name as-is until you plan to update.