So basically the linky link and the checksum need to be updated.It is a bit of a hassle, but here is how to successfully install it.
1. Run the install command as usual, but *DON'T* press Y. (Leave the install script running.)
2. Open up an admin-level Notepad.
3. Open up 'C:\ProgramData\chocolatey\lib\freecad\tools\chocolateyInstall.ps1'
4. Find 'WIN-x64-installer.exe' and change it to 'WIN-x64-installer-1.exe'
5. Save the file but DON'T close Notepad.
6. Go back to the PowerShell window and press <y><enter> to continue the script. It will fail with a mismatched hash.
7. Look in the window for 'Error - hashes do not match. Actual value was' and copy the hash there. (It is the hash for the real installer file.) Mentally note the first few characters of the hash that follows 'did not meet'.
8. Go back to Notepad and look for the hash that starts with the characters that you mentally noted. Replace it with the hash you copied.
9. Save the file and close Notepad.
10. Rerun the altered script.
11. PROFIT!!!
This fix works...but goodness what a bad impression on a new user! That being said thank you to whoever manages the chocolatey packaging, it's been a godsend with the rapid updates of the 0.19 GitHub development packages on Windows for me as a casual user!