They didn't even have to ask if Andrew had succeeded, because before Zaros came out, Elidyr, Lugia, Biacko, and even Crhono had felt a torrent of divinity run through their bodies.
The moment Andrew assimilated the divinity of the deceased god, Andrew managed to release not only his fifth divine seal, but his sixth as well, so everyone close to Andrew received benefits.
When he released his fourth divine seal, Crhono and Biacko had not received benefits, because he did not know them yet, nor were they close, but in this short time that they had known each other, they had created a bond with Andrew, so now they did receive it.
This did not go unnoticed by those present, but it was only when Andrew appeared that they understood what this change was due to. Andrew's mere presence demonstrated what was happening.