Yes, they will still be emailed. The only email related feature that is disabled is mailing mode.
Here is the full blocked user description:
Account flagged by spam system as a problem account, all posting is disabled.
- Account may not reply to any topic
- Account may not create any topics
- Account still can like and flag (TBD if this is a good idea)
- Account can still change user prefs and about me (TBD if this is a good idea)
- Mailing list mode stops working
Note that this is in contrast to suspended users for whom all email (with one exception) is blocked.
Suspended user description (emphasis mine):
Account suspended from Discourse instance
- A note is displayed on user page denoting suspension reason
- Login is not allowed
- Account no longer shows up in search
- No emails are sent to user for any notifications (digest, message and so on)
- As an exception any emails initiated by staff are still sent to user