4.11 "Update" wants to install enirely new copy?

Unreal noob here.
I have 4.10.4 and 4.11.0 installed.
This morning my library says that 4.11 has an update.

I go to 4.11 and click “Update” and it’s telling me it requires 16+ GB of space and there’s not enough room.
And, it’s correct. I only have 13 GB of free space.

Why is an “update” trying to do a complete install?
Is this the way it is with every “update”?

Thanks.

Every time there is a “minor” update (4.10, 4.11, 4.12, etc.), you’re going to have to download the entire thing over again, I believe. However, with “revisions” (4.10.1, 4.10.2, 4.10.3, etc), those will update as though it were patched.

is it an update from a preview version to the full release?

I was updating from 4.11 to 4.11.1.
I have since deinstalled all versions and installed 4.11.1.

Of course, I cannot package even base template-based projects, but that’s in another post.
Thanks for the replise.