I can’t comment on the Episode IX info, but it’s been pretty well documented at this point that other missions have been/are being designed for Smuggler's Run.
It was first reported by Making Star Wars in October 2018, who has historically been a very reliable source for various LucasFilm projects:
Details on the Millennium Falcon ride in Galaxy's Edge, the Star Wars land within Disneyland and Disneyworld.
makingstarwars.net
Then, it was reported again by Entertainment Weekly in one of their exclusives on Galaxy's Edge in November 2018:
Star Wars
ew.com
Also, WDI pretty much acknowledged that there would be multiple missions all the way back in December 2017 at Galactic Nights. They said that you would face off against a giant monster in “just one of the missions you might find yourself faced with”. They also released this concept art:
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