#1 is not accurate but for different reasons.
A forward slip is absolutely required for a PPL checkride and has been for decades (if you'd like a source, see page 45 of the definitive FAA ACS: https://www.faa.gov/training_testing/testing/acs/media/priva...).
However, transport category aircraft (among other issues) have swept wings, which are far less stable in a slip - so slips are neither taught nor recommended for jets.
Looks like forward slip to landing has been in the Private Pilot Practical Test Standards [1] since at least Nov 2011
[1][PDF] https://www.faa.gov/training_testing/testing/test_standards/...
Here's it as a required maneuver in 1995 :)
https://www.faa.gov/documentLibrary/media/Advisory_Circular/...
Edit: I'm dead wrong. :)