Switch is performing as expected. Nintendo is going to ship around 17'0M for the FY18, so Switch has to end around 35M shipped total by the end of March. If Switch has sold 33'0M to consumers by then there will be around 2'0M on shelves, in my opinion a little bit too much by this time of the year (althought perfectly possible). So this could mean three things: a) Switch is not going to reach the goal, b) Switch has sold to consumers more than VGC is showing, c) Switch is going to have that much units on shelves indeed and that will mean Switch is going to sell a lot more than last year in Q1 FY19 to consumers thanks to previous stock left available.
PS4 on the other hand, as time passes seems it's going to end around 14'5M sold to consumers in 2019 if there is no price cut. It's going to be a huge drop compared to 2018, but from Sony's perspective, selling 14-15M consoles at $300 is still as good or even better than what PS3 did in its prime, so maybe Sony will be satisified with this. If there is some important price cut this year, then PS4 can sell around 15-16M, but i'm not confident on that anymore.
XBO is so dead that i still believe XBO won't reach 50M before their successor comes in 2020 (even if it comes in holiday 2020). Considering that, as time passes, i won't be surprised if Microsoft prefer to launch their next console during March 2020 to have an advantage against PS5 launching on the holiday season.