The last model update had this requirement:
a taxon must have at least 100 verifiable observations and at least 50 with a community ID to be included in training
and it only
used images from observations meeting the criteria above on September 29, 2019.
There were 99 verifiable observations on 9/28 and 103 on 9/29, so it’s quite possible it simply missed the cut by a few hours. (Or it’s possible the >50 community IDs were reached on those observations after that time. I didn’t look deeply enough into this to tell.)