Should disks be automaticly available in ASM after disk replacement?

Hi

We did a test, and removed one HDD and one SSD, and put it in again. We saw in EM that it was rebuilding, but after a few hours rebuild was finished but the disks disappeared.

From support we got help, and could add them again with this command:
ALTER DISKGROUP <DG_name > ADD FAILGROUP <name> DISK <'ds_name'> NAME <name> FORCE;

The question I forgot to ask support is, should the disks automaticly appear ? Or is it normal that we must add them through commands or EM ?

If we have a diskcrash and enter a blank disk, is there another routine? I'm sure Oracle technicians will do the job, but nice to know.