The sad thing is, as others have expressed, Disney no longer offers open to close days many days. People are willing to pay for 'extra magic' both in the mornings and evenings so basically Disney is doubling their cash without adding many hours.
Our family is going in December and over 6 days that we are there, the MK is closing early 3 of those nights and another night is offering Evening Extra Magic. What it does is cause us to plan carefully if we want to enjoy the fireworks as they are offered only 3/6 nights.
The good thing is that historically I've found that the MK is quieter during the day on party nights so since we have PHs due to FD offer, we will visit MK on party days then go elsewhere. On non-party days we'll go to another park then bounce to the MK for the fireworks.
It takes planning but is doable. More and more people are willing to pay to go before/after hours so it's just one more thing to plan into our touring plans!