Ah, I think we're down to semantics here :) . Making a broad statement about the "consensus" of something, when actually you mean "My friends think" is not the same thing, and I mean no slight to your friends by that.
Winnick had already estabished that Jason ever being dead was the error in the universe, SBP's punch actually FIXED that one, so having a Monitor use the "He should be dead" bit is contradicting the established status quo. Having a Monitor say it to justify his presence doesn't make it correct, or the original plan.
And I'd say having to showhorn in Jason was a major problem, since instead of your lead characters being the charismatic, trustworthy, sane, natural leader and puller-together of disparate folk Nightwing working with reliable powerhouse Donna, who he'd known and loved like a sister since before puberty kicked in, differs wildly from semi-psycho Jason, who no one on even his own team particularly liked and would be insane to trust, becoming someone that Donna was, IIRC, starting to have more than just team-mate feelings for.
And having said all that, I'll withdraw too! Cheers.