So, here's the report. None of the Y to J upgrades cleared.

At check-in, the three who were not on my locator were offered paid upgrades Y to W (Premium Economy) for $400 each, which we declined. When I (EXP) checked in, I was offered complimentary Y to W for me and the other on my locator, which we accepted and flew.

One lesson for others: had all 5 of us been flying on the same record, and there was space in W available, all 5 could have upgraded for $0 based on what the check-in agent told me. So, split the record to improve upgrade to J chances, but if the upgrade doesn't come through, you minimize the potential Y to W free upgrade.