Looking over photos of other Nvidia dies, it does seem like the four digits in the upper left are indeed the year and week. It matches up with the expected manufacturing timetables for everything I've seen. For example, the following three GPUs:
The line below that seems to change between individual chips of the same model (as evidenced by comparing
this photo and
this photo of two GP106 dies). This may be further manufacturing identification (e.g. the machines used, or perhaps even the individual wafer).
The final line seems to be the only one which determines the chip, which in our case is ODNX02-A2.
It does seem a little strange that fabrication would have started as far back as July last year, but it's not necessarily impossible. With how few other chips are coming off TSMC's 20nm production lines, it's possible that they simply got a good deal to use up the excess capacity, offsetting the logistical costs normally associated with stockpiling components.