Earlier this week, during the NLCS and opening night of NBA action, YouTube TV saw multi-hour outage of the service. Many customers are now reporting that they are receiving a 1-week credit ($10 value) as an apology for the outage.
During the outage, customers were unable to stream YouTube, YouTube TV, or log-in to TV Apps using TV Everywhere. It appears you will have to fill out a form included in the email by October 23rd to request the credit.
Stability has generally not been a concern for the service, but it has had some untimely downtime during major sporting events. This summer customers also received a 1-week credit for an outage during the World Cup Semifinals.