They're never removing seasonal content, the same way they never removed chapters.

If you've been on Reddit you know redditors lie. The same way that every chapter is available for purchase well after they've stopped updating it. Seasons are going to be the same.

What seasons are by the way, is making the world deeper instead of wider. There were so many things left untouched in the face zones that I always wanted. It really became super overt in the High Isle expansion. Just see a lot of people I had already seen and I'm like... "I wonder what they've been up to"

That's what the seasons are going to be. Might also apply to a companion which would be very welcome.

Here is the cliff notes of what was actually typed.

Seasons

We will be talking much more about this in the future, but in 2025 expect to see named Seasons of three or six months duration with a mix of themed story content, events, store items, dungeons and more.
2025 will be a mix of old and new as we move the dev team towards creating smaller bite-sized pieces of content. We will still have some larger items that we've been working on for over a year, which you'll see launch as well.

Change and experimentation

So, we will be experimenting with a Cyrodiil campaign where all classes will have PvP-specific (and more performant) skills that replace the standard player skills with the expectation that we can support more players per campaign. Increasing the difficulty of standard overworld combat Improving the overall feel of combat with animation, FX, and potentially audio work Experimenting with more zones like Craglorn (although not as large in area or scope) Adding and refining tools to make guild recruitment, interaction, and management easier and more logical

New and returning user experience:

Our goal is to shield new players from being overwhelmed by dozens of content options presented to them on entering the world, and instead give them the essential guidance they need to enjoy the game before opening it up to all possibilities.

Additionally, we have many millions of players who return to the game every year after taking months to years off – and it is often confusing to them what they should be doing. We need to address this by making sure that the game’s map and other quest/informational UI areas clearly show the user where they were when they left, what has been added since then, and where they will find content they will love.

Continuing to tell great stories

Continuing the stories in existing zones and storylines and bringing back familiar characters

New stories focused on hallmark Elder Scrolls organizations like Dark Brotherhood, Thieves Guild, Fighters Guild, and Mages Guild

If you want to scrutinize the letter yourself It's literally linked.