Technically, it says that local, non-weather related emergencies can only last for a maximum of 42 days, must be renewed weekly and can not be replaced by a "substantially similar" emergency order. It also states that any local, non-weather related order can be invalidated by the Governor at any time prior to expiration.
For all intents and purposes, it means that no future COVID-related emergency order can be introduced locally. If COVID is still an issue at the earliest time that there is possibly a different Governor and/or legislature, then there is really no point to any order as the State of Emergency will be nearing its third year at that point.
No, it's coming from the State Legislature who wrote and passed the law.