I believe it's certainly possible that Simpsons sticks around for longer, but I hesitate to be so sure either way. Bigger stuff has changed faster in the past.
There is solid backing for both sides. Disney probably has no great opportunities for the IP at their parks, despite really wanting to capitalize on it. "Current World Events™" and a slowing of travel to UOR generally could lead to a slowdown of construction post-Epic. And despite a slowly dying IP, it still seems to be doing some numbers. I always see people posing with Homer and Bart when they pop out, FF Blvd seems to be doing just fine, and I'm certain they're still selling enough Duff and Lard Lad to keep the lights on.
VS. They have definitely been de-emphasizing Simpsons as an IP connected with Universal. There have been very few new merch or marketing pushes with the characters. Meanwhile Marvel gets a ton of push on both angles, so it's potentially not Disney stopping them. Maybe we're just getting antsy and we'll start seeing those solid signs of movement as we get closer to 2028? We're still a good while away from then anyways, and despite it being speculated for years we didn't have a solid idea on the HRRR redo until less than 9 months ago. We're still very fresh off the heels of Epic and HHN34, and they are already working on a USF project right now. Maybe replacements for HRRR and Supercharged are just the opening moves we see completed by 2028. Just in time to prep USF for a years long closure of a major land?
We'll see what happens. It's a very weird moment for speculation right now.