In the new path (snake) configuration, a placement test allows you testing out of several units. These units are not really coinciding with skills but are definitely more concise than Duolingo chapters used to be. After a placement test any access to previous content ("basic" for you according to the placement test result) is only accessible for a 'practice' (which is fairly short) or a legendary lesson.
The idea of a placement test is to measure passive exposure to a language: you think you have a feel for French, Spanish or Portuguese? You can understand some of what you read but you can't speak the language at all? This is what a placement test meant is for. Remember that a placement test used to award only one crown for any skill in the classical tree like structure. You had four more occasions to learn harder content on each skill you tested out of. One single crown is a just reward to avoid basic "guess the picture corresponding to the word" exercises.
The whole idea of acquiring language knowledge through spaced repetition is thrown overboard. A unit tested out of now suggests you have five crowns on each of the skill-like subunits.
Indeed: testing out of a unit now presumes you can both understand, translate exactly both to the instruction language or back into the target language, understand spoken text in the target language and write it down...
Testing out of a single unit later on? Same problem: the sub-skills turn all yellow and you can only do some short practice exercises or turn the unit legendary if you are really that smart.
More than anything else, I miss spaced repetition in the new path / snake approach.
Learning 
(B2-) 
(B1) 
(A)