Acrobat X64 Pro DC: Why the version of the Acrobat is not mentioned in the download site?

I imagine it seems a lot of trouble, for an app which auto updates anyway - the version delivered may not be considered important, or may be considered confusing. 

The current version provided in the download links is omitted because it is usually a major release version that is continuously undergoing through a technical support period; and it serves as a generic product verion.

That being the case, it requires that the user update that version after downloading and installing to reflect the appropriate versioning of the product's release cycle.

The release cycle is associated with the plan that a user have already subscribed to or paid for (classic track or continuous track, for example).

Like with every distributable software, users must make use of the release notes instead to find out the most recent release:

• https://helpx.adobe.com/ca/acrobat/release-note/release-notes-acrobat-reader.html

To understand more about the Acrobat product that you intend to deploy, you should also look into:

• https://www.adobe.com/devnet-docs/acrobatetk/tools/ReleaseNotesDC/index.html

And the Document Cloud Product Track:

• https://www.adobe.com/devnet-docs/acrobatetk/tools/AdminGuide/whatsnewdc.html