Why delaying Norway would change more than French reinforcements

If Norway fell three weeks or a month later and Germany invaded France later, would France send more forces to Norway?

Possibly, but the delay changes too many connected events for a narrow answer; Norway's readiness and response to threats are central to the scenario.

Awareness of possible threats should have produced alert measures, rules of engagement, and rapid warning after Denmark's invasion. British concern about Norwegian intentions did not justify every British plan, but it reflected a genuine fear that key ports might not be defended. Moving the invasion date by several weeks also changes the French campaign and the availability of Allied forces, so reinforcement cannot be isolated from the wider timetable. Neutrality amid rival threats still required commands, communications, and defended access points.