The process to send things to GBIF has multiple steps. After an observation qualifies, the next time iNat generates an export for GBIF, it will be included. This happens weekly. Then GBIF has to ingest the new export. This is also supposed to happen weekly, but iNat has no control over it. (You can see the ingestion history here.) Then once the record is in GBIF, iNat has to read back in the GBIF number to create the outlink back to GBIF. Tony said this happens monthly, but it seems like sometimes it takes longer than that.
At any rate, https://www.inaturalist.org/observations/308414953 is already in GBIF, the thing that’s missing is the outlink where iNat knows the GBIF occurrence number.