The "failover and failback for business continuity" is specifically for cross-region/cloud, i.e. this is something you explicitly have to do. tbh I've never used it, as I guess this would be only for very large accounts. But all editions have automatic failover between AZs out-of-the-box.
[Edit] Highly Available would be a better description per region, as that's out of the box with no configuration. e.g. if a node dies, your cluster will automatically heal and resubmit your query. If there's an entire AZ outage, your query should be resubmitted in another AZ. I think this is why failover/back is called out separately, as that's not automatic, incurs additional costs etc.
Here's a link with an explanation: www.snowflake.com/blog/how-to-make-data-protection-and-high-availability-for-analytics-fast-and-easy
I didn't know DB did MVs, masking etc., so yes, that makes sense. Maybe a better idea would be to have a minimum offering comparison, and then a maximum offering comparison (with multi-AZ failover, masking feature costs etc. included) - the reality for a customer would be somewhere between those extremes.
