Speaking at a lunch for regional journalists, Mr Corbyn said it had been "like playing multi-dimensional chess".
Two other North East MPs have been promoted by Jeremy Corbyn.
Jeremy Corbyn backed down from sacking his shadow foreign secretary today but faced criticism from members of the shadow cabinet for ousting Michael Dugher, his shadow culture secretary.
Ms Thornberry, the Islington South MP and shadow employment minister, had been tipped to take over from Ms Eagle - who has had her own differences with Mr Corbyn over the future of the UK's Trident nuclear weapons system.
Another member of the shadow cabinet, culture spokesman Michael Dugher, was earlier sacked.
Denying he had staged a "revenge reshuffle", he instead told regional journalists his move - which prompted three frontbench resignations - was merely an "adjustment".
McFadden was criticizing the response of the Stop the War Coalition, which Corbyn used to lead. Legislator Jonathan Reynolds later resigned as Labour's railway spokesman, saying he wanted more freedom to speak out.
Shadow foreign office minister Stephen Doughty quit the Labour frontbench live on television.
Last night Ms Eagle made no comment as she left a meeting with Jeremy Corbyn.
Members of his "shadow cabinet", who hold portfolios mirroring those in government, had openly disagreed with him over foreign and defence policy - something that has hobbled the party's ability to challenge the ruling Conservatives. "But clearly the front bench is geographically a little bit unbalanced now".
But appearing on the Jeremy Vine show on Radio 2, Mr McDonnell accused the rebels of being linked to the Blairite campaign group Progress.
The shake-up has been regarded as an attempt by Mr Corbyn to stamp his authority on the parliamentary Labour party.
"I've had lots of conversations with Hilary Benn and we get on fine", the Labour leader told The Yorkshire Post. But he added that Labour was a "broad church" and there was room within the party for those views to be debated.
Mr McFadden told Sky News he had never rebelled against the Labour whip in 11 years as an MP and had been keen to do his duty and fight to keep Britain in the EU. Thornberry has voted against renewing Trident.
She says she was against the 2003 invasion of Iraq but supported the initial airstrikes against Islamic State in the country because "we have a responsibility for what's happened in Iraq and what is essentially a baby democracy". She received a £14,500 donation from the firm between September 2013 and March 2014 to pay for a legal research assistant for her office when she was shadow Attorney General. "So I'm anxious that this just reinforces this sort of drumbeat which is internally focused, which is factionalised, which is sort of symptomatic of a coarsening language and a lack of ideas at the top of the party".
"I'm afraid they haven't respected that leadership election result". Does it help us defend ourselves against 21st century threats?
4.3 magnitude earthquakes rattles Southen California
But a USGS seismologist now says more big earthquakes , magnitude 4.0 or even much larger in the same area are likely. The City of Vancouver has tweeted that there are "no known reports of significant quake damage".
Pakistani MP Appointed As British Shadow Minister
