when u re-pot give em a good watering in with water that aint to cold,, it will get rid ov air pockets in the soil,,
u might think an air pocket is good and that roots will get oxygen from it but it isnt,
its a pocket of stale miost air wich will grow mold over time
after that leave them till its dry and u will see roots come to the bottom of the pot looking for moisture and exploring the new soil,,
if u dont let it dry the roots will just stay in the old soil and not go in to the new stuff and then at worst u will have root rot...
iv just moved up pot size my self it will be 7 days'ish till i water now,, if no roots come to the bottom in the 7 days in know they still got moisture in there,, soon as i see some roots coming threw ill know theyre looking for water and ill stil probly leave them a couple ov days untill lots of roots are there until i give em a drink