Not true ... flyers ignore characters for movement, but still have to break away.

Correct, because Flight allows the use of the Improved Movement of the paired circles w/ arrow through them, which expressly states "...still needs to break away normally..."

The Improved Movement symbol of <BLACK CIRCLE> ignores characters for all movement purposes.

Incorrect. Flight does not ignore characters at all. Instead, here is what Flight actually does:

FLIGHT
This character can use IM [hindering terrain], [elevated] terrain, [outdoor blocking terrain], OO> . An elevated character using this ability ignores knock back damage if its knock back path crosses the boundary to a lower level.

All of those are pretty self-evident with the exception of OO>, so let's look that one up. From the IM/IT table in the PAC:

May move through squares adjacent to or occupied by opposing character but still needs to break away normally.


Nothing in that description says anything at all about "ignoring".

If Flight truly did ignore characters, a character using Flight wouldn't need to worry about stuff like KC/Hypterime TA, moving adjacent to Gert and Old Lace, etc.

Omg so the improved movement that allows ignoring characters won't tigger theses SP's? What about deathstroke's SP? If so then night wing and batman just got crazy good better.

So flight ignores characters as they move adjacent and past them, but not once they stop adjacent. At that point the ignore stops and they must break away.

No, "ignore" is a game term. Flight doesn't ignore. It matters, from previous examples and more, like FI Heimdall. Terminology matters.

Going back to the original question...because I am very confused as to whether or not it was definitively answered...can Improved Movement be Outwitted?

Yes, it can.

Which is supported by the following two things, both from the PAC, Bold text is mine for emphasis.

OUTWIT
Give this character a free action to counter a power or a combat ability possessed by a single target opposing character until the beginning of your next turn.

and

COMBAT ABILITIES
Improved - Improved Movement, Improved Targeting (see the
character’s character card for how it can use these)

Outwit can counter a Combat Ability. Improved Movement and Improved Targeting are Combat Abilities. IM and IT can be countered.

Correct. Improved Movement and Improved Targeting can both be outwitted. They are separate abilities however, so if a character has both IT and IM, they must be countered separately.