I believe the exception that might apply to your- OP- case is if the test account was set up as a guest account. I don't know for sure but I would guess that TM wouldn't backup a guest account... only true ADMIN and User accounts.
For example, if there were 2 users + a guest account, I would 100% expect TM to backup the 2 users but not necessarily the guest... as guest is usually an account set up for only temporary access such as by someone visiting and needing a computer for a while but you want to mostly lock them out of access to your own files and/or having the ability to add/delete apps to the system.
That shared though- I don't know this for sure. I'm speculating based on how user accounts work and the suggestion that if "test" was a guest account instead of a true user account, it might NOT be backed up too. If you want test to be backed up too (and it is not), you can easily switch it to a user account.