Per this statement from DJI, they are aware of the upcoming GPS week rollover and have confirmed that DJI drones will not be affected by the week rollover.
What is the GPS Week Number Rollover (WNRO)?
Garmin explains it like this:
The GPS system is world renowned for its ability to provide accurate and reliable positioning and timing information worldwide. The GPS satellites transmit to users the date and time accurate to nanoseconds. However, back in 1980, when the GPS system first began to keep track of time, the date and time was represented by a counter that could only count forward to a maximum of 1024 weeks, or about 19.7 years. After 1024 weeks had elapsed, this counter “rolled over” to zero, and GPS time started counting forward again. This first rollover occurred in August of 1999. The second rollover will occur on April 6, 2019.
Want to learn more about WNRO? Check out this article from Lisa Perdue, a world-leading expert in testing critical GPS and GNSS systems: