That is true, but the maintained status only allows you to continue working under the same conditions as your old expired permit. If you're on a work permit tied to a specific job then you won't be able to start a new one until you actually get your BOWP. Plus, you may not get provincial health care coverage while in maintained status—last I heard of it, it's at the discretion of the individual offices. So yeah, having applied for it gives you some rights and you absolutely should do it, but actually getting it is a lot better.