ios - When will Apple start rejecting apps built with Xcode 4.x? -

update

on december 17, 2013, apple has issued statement when forcing submit new apps xcode 5:

"starting february 1, new apps , app updates submitted app store must built latest version of xcode 5 , must optimized ios 7."

ios 7 announced on june 10, 2013, xcode 5.x being released on october 22, 2013. spans time frame of close 8 months between announcing ios 7 , enforcing xcode 5 submissions, release of xcode pretty nicely in middle.

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original question

apps built xcode 4.x (targeting ios 6.x sdk's) run on ios 7 in kind of legacy-mode, emulating features black status bars, old uiswitch appearances etc. don't know if mode documented somewhere name or maybe not discussed due nda-restrictions, can't find details (upvotes canonically accepted name of mode).

if compile same app without modifications xcode 5, gets compiled first class ios 7 citizen, new status bar appearance , controls. in fact, can't find way in xcode 5 have app launch in legacy-mode (i'll upvote comments non-nda-violating hints on this, real question else).

the app i'm working on works in legacy-mode, crash when compiled xcode 5, due old ios 4.x code. can addressed of course, short deadline client has asked me not address it, focussing on set of features first, , after updating project 'real' ios 7 app.

when weighing rumors , experiences in past years, ios 7 launch supposedly imminent. absolutely vital updates i'm working on submitted app store ios 6 update. current knowledge, means app has built xcode 4, inherently base sdk set tot ios 6.x (or iphoneos6.1 it's called in build settings).

i'm assuming apple @ point around launch of ios 7 start rejecting apps built xcode 4 , ios 6 sdk, in order push adoption of real ios 7 apps, phasing out necessity of legacy mode. i'm hoping aim ios 6 app submission before start rejecting 'old school' apps, have no real intel on when might be.

so here comes real question:

are there examples of cases these prior ios releases, apple started rejecting apps built older xcodes or sdk's? time frame between release of ios version , when apple rejects apps i'm interested in.

p.s. here's forum post seemed indicate happening around launch of ios 6, last post devalues it: http://www.cocos2d-iphone.org/forums/topic/apple-dev-support-says-all-apps-must-now-be-built-with-ios-6-sdk

p.p.s there's date when apple started rejecting non iphone5-optimized apps, had nothing sdk change, let alone major version change 6 7: http://thenextweb.com/apple/2013/03/21/after-a-year-of-warnings-apple-will-no-longer-accept-any-apps-that-use-udids-as-of-may-1st/