Exactly so. The franchise goes up and down. But fans continue on, engage with the products, creating within it, having discussions, or debates.That's how franchises work. There are always ups and downs. They just need to have something that makes as big of a splash as TOS, TNG, and the Abrams Films. All three of which, if you look at the pattern, happened a little over 20 years apart. 1966, 1987, 2009. Enough time to gain a new audience in sufficient enough numbers to replace any old audience that's lost.
To me, there is nothing substantial that will change if there is a change of ownership. Fans are built in, and seek to create that community despite any productions going.
I've been engaged with fans for 30 years now. I see more opportunities for engagement not less.
Mileage will vary.