the PWM of sk6812

Those LEDs are not PWM controlled. PWM would be a fixed-frequency signal whose duty cycle (ratio between high and low level) carries a pseudo-analog information.
Those LEDs are digitally controlled. They require a perfectly timed bit stream. The first in the row will swallow the first 24(!) bit coming in with an exact baudrate, for its own configuration. All further bits are passed-on to its output for the next one in the chain. If the data stream is interrupted for some time, all devices reset the communication and the first one will again swallow the first next bits coming in.
You will have to use SPI, set to an exact baudrate and send it without any interruption. so you will need an MSP with USCI module that offers one-byte double-buffering. And clean, efficient code.
I thought of making a light strip for a POV (persistence of vision) project form these LEDs myself. I'm not sure whether they use exactly the same internal controller, but at least the same generic principle.

btw: the price shown there for 1000pcs is great. I pay more than half of it for just 100.