Can you retrieve datapoints if you missed them during the mission?
According to the IGN wiki, it looks like I missed a hologram datapoint during the Deep Secrets of the Earth mission. The wiki says it is automatically obtained, but somehow I finished that mission without triggering this one:
DATAPOINT 13 - GAIA LOG: 5 JUNE 2065
Can I still retrieve this datapoint after the mission has completed?
Yes, you can return to the Zero Dawn facility at Sunfall after the Deep Secrets of the Earth mission. You can't use the original entrance but an alternative entrance should be shown on your map.
If I remember correctly the three log entry hologram datapoints are in Elisabet's office and, yes, they can be missed.