Is the LEGO Mindstorms Education (not Home, not Scratch based) Edition for Mac OS gone?
It looks like LEGO have indeed completely pulled the previous version.
According to the announcement last year (emphasis added):

Mac Catalina Issues
[…] We have therefore decided to replace the current EV3 Lab software and EV3 Programming App with a completely new app, called LEGO® MINDSTORMS® Education EV3 Classroom. Featuring a coding language based on Scratch, EV3 Classroom will initially launch for macOS in November 2019 and in spring 2020 for iOS, Windows 10, Android and Chrome. EV3 Classroom will offer a consistent experience, features, and content across all devices.

As such, it would appear that this is the only official release you can now download for MacOS from their site.
If you have not yet upgraded your Mac to Catalina, you might be able to use the Mindstorms Lab download from the Retired Products section, where the same warning is included.
If you're unable to locate it on the Retired Products section, a direct link may be available here: LME-EV3_Full-setup_1.4.2_en-US_OSX.dmg