Minecraft 1.17 is the first part of the Caves and Cliffs update. The server world will not be resetting until the second part is released.
Minecraft 1.17 is the first part of the Caves and Cliffs update. Much of the features have been delayed until the second part. The next update will feature all the changes planned for world generation, with all new underground cave and mountain generation and build height changes.
You can read all about the changes here: https://minecraft.fandom.com/wiki/Java_Edition_1.17.
The world will not be reset until the second part of the update is released around the end of the year. The second part will drastically changes world generation. This will allow for all the changes to be fully utilized. To make use of the new features in 1.17 you will need to find new chunks. This should be fairly straightforward with the available world map.
To encourage exploration to the new chunks I will be sponsoring transportation systems to new chunks to help ease the burden of taking on such a large project. Contact me to submit your proposal for a transportation system and I will work out funding.
The server itself will update to Minecraft 1.17 once PaperMC has a functioning build. Until then it will remain on Minecarft 1.16.5. I will be posting on Discord once the server is updated.