I have absolutely no insider info here, just a very strong gut feeling, but I'd gamble the ride that could replace the Laughing Dragon location would be a Booster, like the Catwoman Whip in SF St. Louis.
Just basing it off the SF trend of placing the same ride at multiple parks (like the giant Larson Super Loopers, and Giant Discovery/Frisbee rides). Plus, I'm guessing it'd be relatively cheap (compared to a new coaster), not much else would fit on that location, and--being on the top of a hill--it'd be a great location for one. I also looked at the area from that point of view, and it appears it could be situated without needing to clear out many trees (if any at all). I should add that I'm not necessarily a huge fan of this ride, but I can see it making sense.
By this logic, a Sky Screamer would also be a pretty good bet, but it'd also need a larger loading platform, while a Booster would need a pretty small one, so it'd be even more economical for the park.
Bummer to hear the new entrance is pushed back... kinda really needs one. Along with that repaved parking lot they promised in 2018.
And I won't be surprised if, sometime in the future, an Endeavor appears in the old Tidal Wave spot. Again, no inside info, but SF has put that ride in nearly every other park, SFMM really needs more flat rides, and it looks like it'd be a good fit for that space.
As for Ninja, I'd defintely miss it, but it'd be understandable as it's got to be difficult to maintain such an old attraction, and spare parts have got to be getting scarce. However, people have also been sounding the death knell for Viper for a long time for the same reasons, yet it still seems to be hanging in there... so who knows?