Consumer Reports applies the term "Recommended" to products that test well. The "Not Recommended" moniker is rarely used, and applies only to products that are really bad; to be so labeled, a product has to do worse than to simply not make the Recommended list; it has to be dangerous, extremely unreliable, or otherwise awful. To the best of my knowledge, CR has not put any Tesla into that category. Of course, a product that is not on the Recommended list is by definition not Recommended, but that's different from being in the separate "Not Recommended" list. AFAIK, CR has no "Highly Not Recommended" category. I think it's important to get the terminology correct, since CR has specific things in mind for the three categories of "Recommended," no recommendation, and "Not Recommended." Unfortunately, "Not Recommended" sounds like it would be anything not in the Recommended list, which can lead to confusion, but that's not the case. Fortunately, few products fall into that category.
That said, I think you may be referring to, but imprecisely reporting, the reliability score, which CR reports on a 5-point scale using graphics from red (bad) to green (good), but I'll refer to as 1 (bad) to 5 (good) for clarity in text. The Model X currently gets a score of 1. The Model 3 got a score of 3 originally, but that dipped to 2 after a few months. Historically, the Model S has gotten anywhere from a 1 to a 3. (The 2018 production -- the most recent reported so far -- gets a 1. Apparently the model's been suffering from some recent design changes.)
Reliability is only one factor in CR's car tests, albeit an important one. In order to make the Recommended list, a car must have an average (3) or better reliability rating, but that's not the only factor. The Model 3 and Model S have both achieved a reliability rating of 3 some years (or months, for the Model 3) but not others, which means both of those cars have been Recommended at one point or another; but neither currently makes the grade. Teslas, and especially the Model S, shine in most other categories, including customer satisfaction (another survey result, from the same users as, but independent of, reliability ratings), crash tests (based on NHTSA and IIHS data), and road test (acceleration, braking, handling, seat comfort, etc.; as tested by CR).