Sounds like Intel's new marketing strategy. If you want the latest and greatest, you will have to fork out big $$ for a license. Otherwise you will have to wait (weeks? months?) for the Lite version to become available. Welcome to the new world of Intel, Altera folks!
As of now, Intel's targeting the v19.1 release for the latest FPGA - Intel Agilex as well as the 10 series I guess. It takes a lot of time and effort to release a new device and corresponding software for them.
There may be Lite and Std releases of v19.1 in the near future.. but it will definitely take time. Till then using 18.1 for older devices is good enough.
This is not really an intelPSG issue - ALTERA also released years ago a Special Quartus Edition only supporting the newest high end Chips (not sure if that was for Stratix or Arria to be honest). The main difference was in communication, as that new version was announced with the additional Information this release is only for those devices. This is what I miss now - the v19.1 is announced to be the newest version, advertised with Features to ease design work,... For sure, this draws interest from all of us to that release.
Then - when you want to download that Version: You are frustrated, as it seems to be only for those willing (and able to) buy the full license… As I will not use Agilex devices (we do motorcontrol stuff with Cyclone V/10 or MAX10 - price sensitive stuff) the info "currently for Agilex only e.g." (or even a list which devices are supported, thus you can see "not for me now for missing device support") would prevent frustration...
Sometimes it is not the stuff itself, even in technical business it is sometimes up to communication and presentation skills ;-)
Finally, It's like with the high-end (biggest sizes, ...) devices not being supported in the Lite Edition. If one uses FPGAs which are (for their size and features) sold for many hundert bucks, a professional licence should be within the development costs/budget. Contrary to this if your designs are for devices less than $50, than some thousend bucks for the license are a no-go...