SM is pretty easily going to end by November given the current pacing.
It's really not.
Ash will have finished the third trial by the start of June. There's 20 episodes from then until mid November
There are still episodes for the following Ultra Beasts needing to be done. They're being done one per episode: Blacephalon (in June), Xurkitree, Pheromosa, Kartana, Guzzlord, Stakataka, Naganadel. That's 7 episodes of the 20 done right there
There's been the implied arc featuring Necrozma, as shown by the artwork showing Dusk Mane and Dawn Wings Necrozma, and in Thursday's episode hinted at Ultra Necrozma. That's probably at least 3 episodes right there.
Now there's Mina and Poni Island Grand Trial to do. Based on the Akala and Ula'ula arcs, that'll be between 4 and 6 episodes. Plus a Tapu Fini episode
A league typically takes between 6 and 10 episodes to complete.
Ash & Kiawe, both interested in taking on the league, don't have a full team so there would need to be captures and some evolutions in episodes too. Same with Gladion.
Even if there are zero fillers, it's cutting it way too close. That's also leaving no room for the building Team Skull stuff.
There is no way in hell the Sun & Moon anime is ending this year