Yes, a big part of it is cost savings, not only in less closures, but less fallout, and therefore less safety zones both on stage and backstage. That requires less labor, and more onstage being open allows better guest flow.
The new show was to address a few things. One was a desire to have a show that could operate 7 nights a week, even on slow weeknights. (The city of Anaheim limits the amount of days High level fireworks can be used). Also the financial end, a slow day show has to be fairly inexpensive to run. Also weather, this time of year you can have forced cancellations due to rain and/or wind. This show allows the non-fireworks show segments to operate on those days. Also, you can operate it after 10 PM, due to the fact Firework permits prevent them from being used after 10, even mid show.
So money and operations had major influence over the new event.
And expect it to be the norm. Major fireworks in peak summer, and more multi-media events the rest of the year.
