But it is a fairly recent change on iNat, to use the photo file name as a prompt.
Okay. Not so recent. November 2019
https://forum.inaturalist.org/t/extract-species-name-from-photo-filename-upon-upload/6510/13
Promptly followed by
https://forum.inaturalist.org/t/opt-out-of-taxon-id-autofill-from-photo-filename-on-upload/10123