I'm so disappointed the sims is potentially ending next year,

What makes you think Sims 4 will end next year?
A pre-teen stage would only last a couple days so not really worth it. Height sliders are problematic though I hear that there are mods for this that mostly work.

There's a rumor going around that Sims 4 is ending in 2026 and a newer version is coming also I can see that for short players Sims who play like that but as for myself I see Preteens as another Lifestage like infants and toddlers were added. Just like what's the difference between a YA and an Adult besides the Adult looking slightly older? 

There is posts from a well known…for want of a better word insider, who indicated that the last Expansion pack will deal with Royalty, Medieval themes etc. This person is generally accurate and a trusted source. This will come next year and everything else that follows will be some kit or another. 

I'm happy about that because game cant take more dlcs or big updates, starting fresh could be nice with open neighbourhood colorwheels etc.

Colorwheels was the worst thing in Sims 3, I would not like to have it back in Sims 4! Took too much CPU, and it took me forever to change certain colors and can't say anything else than that was terrible.

Exactly, couldn't agree more! - Pre-teen stages are nothing else than a childish thing to demand, wouldn't be surprised if that mostly was "pre-teens" themselves who wish that. Who want's your sims to be stuck in that kind of stage, when the normal thing in Sims is to became a teenager, youth, then an adult and at last an elder? And even after that, there are many other alternatives.

The person you're referring to is of course Pixelade, who is more of a critic of The Sims than anything else these days - he's spreading a very negative view of the game. I liked what he said before, but not anymore. And without saying any more, everyone knows why. It's his livelihood that's at stake. Even today, he can't let The Sims 4 alone...

You can have your opinions about Preteens and I would assure you that most simmers that are asking for Preteens such as myself are not a Preteen. 

 Now have I seen Preteens asking for their Lifestage to be represented in the game? Yes they want to represented in the game just like anyone else which made me add more fuel for wanting Preteens in the Sims PC Franchise. It's the reason why they were put in with InZoi and Paralives when it comes out. 

I mean it's the Sims it's anything but normal as you said yourself you can do other things after elder but Preteens is where y'all draw the line of doing any else? 

Most of the people got there info from Sims Community on X/Twitter they posted an article about it. Late November early December it was an article about changes coming to the Sims 4 Base Game with Open Neighborhood, and Seasons and I think Milestones.

SimMattically around September, October time said that this will be the last EP for awhile which back in the day it was one EP an entire year with SP and GPs.

Now Sims Community came out with another article saying that the Sims 4 is ending this year but another Sims 4 Base game is updating. 

Of course it depends on who you are and how you wish to play, but I don't think you know more about that than I do. I've also seen sporadic posts about pre-teens, but I wouldn't say it's dominant in any way. The Sims is so complicated as it is now, we have more options than ever and there's lots of things to do without an unnecessary stage of life like pre-teens. 😉