Just see the game notes for the TripleA map of Global 1940 2nd Edition.
There it says:
@Game:
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Below is a list of rules that the TripleA game engine either does not enforce, or enforces incorrectly, at this point. Each item starts with a code in parentheses that represents how you may fix or correct the rule.
(PE) = Player Enforced = You must be aware of the rule and must follow it. The engine will not stop you from breaking the rule.
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Rules specific to 1940 the engine does not do, but you must follow:
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(PE) You are not allowed to blitz or move any units through Friendly Neutrals, including the same turn they are captured, unless they have been previously attacked.
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So it is true, TripleA “allows” your move, but players have to be aware that it is against the rules (and for this drop it).