The reopening date hasn't changed though... based on the first dates posted at the beginning of this thread, so instead of a 3 month downtime, it's only 2 months.
Meanwhile (again based on the starting dates shown at the beginning of the thread):
Carousel has been extended by a week to 30 June
Green Lantern has also shortened by 3 weeks moving back from 22 July to 12 August.
Tweety cages were supposed to be down until 3 June, and that's been extended to 1 July
Dodgems were 5-19 August and are now 3 June to 24 November
I assume something in the current or recent maintenance has prompted a reshuffle, and they've probably put off some less critical tasks in AA and GL to shorten their maintenance periods. An original three month closure for Arkham seems excessive unless they had planned a big project like a repaint, or a full track inspection...