Id have him contact his travel coaches and have them reach out to the other schools who recruited him and see if they would be interested. Entering the portal with no college stats for the current season and little from the COVID season prior is not an enticing resume. If there are no opportunities elsewhere,staying to not risk hours that don't transfer may make sense. The grass isn't always greener. If those other schools are interested, travel coaches can tell him when to enter.
Right now I don't know if college coaches have time to look at the portal because they're very busy with their team. but if you wait you will be competing for attention against Everyone else who waits until the season ends as well as JUCO guys. So I don't know.